Helium Chemistry: A Survey of the Role of the Ionic Species

Abstract The ion chemistry of helium currently embraces a large variety of species, mostly cationic, which range from simple small-size molecular fragments or complexes to large-size cluster ions and encapsulation products. These species are usually observed under the isolated conditions of the gas phase or theoretically investigated by high-level of theory calculations. In the current years, the highest interest is focused on classical topics such as the interaction between helium atoms and monoatomic, diatomic, and simple polyatomic ions as well as on research themes which have more recently emerged, such as the study of ionized helium clusters and the fullerene-helium chemistry. The aim of the present article is to give an account of selected recent advances in these fields and to put them in the perspective of the previous most relevant acquisitions concerning the ion chemistry of helium. In particular, the literature covered here concerns the ionised helium clusters Hen+ and Hen− (n ≥ 2), the hydrogen-containing helium clusters HenH+ and HenH− (n ≥ 1), the adducts of one or more helium atoms with a variety of singly- and multiply-charged monoatomic, diatomic, and polyatomic ions, and cage compounds such as He @ C60+ and other related cationic and anionic species.

[1]  F. Grandinetti,et al.  Beryllium–helium cations: computational evidence for a large class of thermodynamically stable species , 2003 .

[2]  Edmond P. F. Lee,et al.  Al3+ · He: stability and spectroscopy , 2004 .

[3]  N. Kobayashi,et al.  Helium cluster ions RgHex+ (Rg=Ne, Ar and Kr,x≦14) formed in a drift tube cooled by liquid helium , 1992 .

[4]  P. Stancil,et al.  Stimulated Radiative Association of He and H+ , 1998 .

[5]  R. D. Poshusta,et al.  Ab Initio Calculations on He2H , 1971 .

[6]  M. Viant,et al.  Microwave spectroscopy and interaction potential of the long‐range He...Ar+ ion , 1995 .

[7]  G. Frenking.  Chemistry: Another noble gas conquered , 2000, Nature.

[8]  E. Sanville,et al.  Computational studies of possible transition structures in the insertion and windowing mechanisms for the formation of endohedral fullerenes , 2003 .

[9]  W. Lindinger,et al.  Vibrational relaxation in the NO+–He collision system: Implication of the Gislason–Ferguson model , 1995 .

[10]  M. Meuwly,et al.  Predictions of microwave and far-infrared transitions in He-H+2 , 1999 .

[11]  P. Wormer,et al.  The interaction potential and transport properties of Na+ ions in He gas , 1994 .

[12]  J. Murrell,et al.  Unimolecular dissociation dynamics of helium cluster ions , 1998 .

[13]  J. Morales,et al.  Vibrational motion in isotopomers of the HeH+ molecular ion: An application of the electron nuclear dynamics method , 1997 .

[14]  C. Benoit,et al.  The He++H2→HeH++H*(2s,2p) reaction: Study of the s and p contributions in a coincidence-correlation experiment , 1998 .

[15]  E. P. Hunter,et al.  Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update , 1998 .

[16]  J. Hernández-Rojas,et al.  Low-temperature dynamics and spectroscopy in exohedral rare-gas C60 fullerene complexes , 2001 .

[17]  O. Dopfer,et al.  Internal rotation in NH4(+)-Rg dimers (Rg = He, Ne, Ar): potential energy surfaces and IR spectra of the nu 3 band. , 2001, Faraday discussions.

[18]  T. Tsong.  Pulsed-laser-stimulated field ion emission from metal and semiconductor surfaces: A time-of-flight study of the formation of atomic, molecular, and cluster ions , 1984 .

[19]  A. Carrington,et al.  Infrared predissociation spectrum of HeNe , 1985 .

[20]  L. Viehland,et al.  AB INITIO CALCULATION OF THE GAS PHASE ION MOBILITY OF CO+ IONS IN HE , 1999 .

[21]  E. Campbell,et al.  Collisional energy dependence of He capture by internally excited C60 anions , 1994 .

[22]  M. Elford,et al.  Interaction Potential and Transport Coefficients for Li+ Ions in Helium , 1999 .

[23]  G. Groenenboom,et al.  Theoretical study of the He-HF+ complex. II. Rovibronic states from coupled diabatic potential energy surfaces. , 2004, The Journal of chemical physics.

[24]  Mitchell,et al.  Measurement of the ultrashort bond length in He2++ , 1989, Physical review letters.

[25]  L. Radom,et al.  Multiply-charged helium-containing cations: HeCO2+, HeCF3+ and HeCNe4+ , 1987 .

[26]  R. D. Poshusta,et al.  Ab Initio Predictions for Very Small Ions , 1969 .

[27]  K. Hiraoka,et al.  Gas-Phase Solvation of O2+, O4+, and O6+ with Ar , 1995 .

[28]  P. Rosmus,et al.  Rovibronic energy levels of HeHF+ (X 2Π) , 1994 .

[29]  C. E. Dykstra.  The strong hydrogen bond in HeHHe+ and its weak counterpart in HeH+3 , 1983 .

[30]  K. Sakimoto.  Isotope variations of exchange and dissociation reactions in collinear He + H2+ collisions , 1996 .

[31]  J. Toennies,et al.  Spectroscopic observation of a metastable electronically excited He4 , 1995 .

[32]  E. I. Nagy-Felsobuki,et al.  Rovibrational states and vibrational intensities of the χ 2A1 state of He2C3 , 1999 .

[33]  Di-Jia Liu,et al.  Rotational spectroscopy of molecular ions using diode lasers , 1987 .

[34]  F. Cacace.  Nuclear Decay Techniques in Ion Chemistry , 1990, Science.

[35]  N. Sathyamurthy,et al.  Dynamics of the endothermic reaction He+H+2 →HeH++H on an accurate ab initio potential‐energy surface , 1987 .

[36]  D. L. Cooper,et al.  Noble gas molecular ions , 1981 .

[37]  D. Cremer,et al.  Helium chemistry: theoretical predictions and experimental challenge , 1987 .

[38]  M. Thachuk,et al.  Molecular dynamics study of the collision-induced rotational alignment of N2 + drifting in helium , 2001 .

[39]  Helmut Schwarz,et al.  Endohedral fullerene-noble gas clusters formed with high-energy bimolecular reactions of Cxn+ (x=60, 70; n=1,2,3) , 1992 .

[40]  F. Gianturco,et al.  Quantum and classical structures for 4He clusters with the H- impurity , 2003 .

[41]  P. Bernath,et al.  Detection of the infrared fundamental band of HeH , 1982 .

[42]  A. Buckingham,et al.  Comment on: “The ν3 infrared spectrum of the HeNH4+ complex” , 1997 .

[43]  Walter Thiel,et al.  Radical Impurity Mechanisms for Helium Incorporation into Buckminsterfullerene , 1997 .

[44]  T. Tsong,et al.  Energy distributions of pulsed-laser field-desorbed gaseous ions and field-evaporated metal ions: A direct time-of-flight measurement , 1984 .

[45]  P. Fuentealba.  Calculation of alkali-ion-rare-gas potentials: the LiHe+ ion , 1986 .

[46]  P. Wormer,et al.  The non-empirical calculation of second-order molecular properties by means of effective states. II. Effective TDCHF spectra for NO+ CO, CO2, and C2H2 , 1985 .

[47]  Davidson,et al.  Ground-state correlation energies for two- to ten-electron atomic ions. , 1991, Physical review. A, Atomic, molecular, and optical physics.

[48]  D. Bohme,et al.  Experimental results for ion-molecule reactions of fullerenes: implications for interstellar and circumstellar chemistry , 1993 .

[49]  F. Albert Cotton,et al.  Advanced Inorganic Chemistry , 1999 .

[50]  K. Jordan,et al.  Theoretical potential energy curves and spectroscopic properties of the X2Σu+ and A2Σg+ states of He2+ , 1986 .

[51]  Wing,et al.  Observation of the infrared spectrum of the helium molecular ion (3He 4He)+ , 1987, Physical review letters.

[52]  S. Leone,et al.  Rotational-state and velocity-subgroup dependence of the rotational alignment of N2+ drifted in He , 2001 .

[53]  Walter Thiel,et al.  How Does Helium Get into Buckminsterfullerene , 1996 .

[54]  J. Almlöf,et al.  The interatomic potential for the X1Σ+ state of ArNa+, NeNa+ and HeNa+ , 1995 .

[55]  V. Špirko,et al.  Radiative association of HeH2 , 2003 .

[56]  J. Futrell,et al.  Reactions of rare-gas hydride ions with ethylene , 1976 .

[57]  L. Wolniewicz.  Variational Treatment of the HeH + Ion and the β-Decay in HT , 1965 .

[58]  M. Bowers,et al.  Determination of potential energy curves for ground and metastable excited state transition metal ions interacting with helium and neon using electronic state chromatography , 1992 .

[59]  Many-electron correlated exponential wavefunctions. A quantum Monte Carlo application to H2 and He2+ , 1995 .

[60]  M. Beyer,et al.  Trihydrogen cation solvated by rare gas atoms: RgnH3+ , 1999 .

[61]  L. Radom,et al.  Remarkably stable trications and tetractions: the triheliomethyl trication (CHe3˙3+) and tetraheliomethane tetraction (CHe44+) , 1987 .

[62]  J. J. Turner,et al.  Krypton Fluoride: Preparation by the Matrix Isolation Technique , 1963, Science.

[63]  M. Gross,et al.  INCORPORATION OF HELIUM INTO ENDOHEDRAL COMPLEXES OF C60 AND C70 CONTAINING NOBLE-GAS ATOMS : A TANDEM MASS SPECTROMETRY STUDY , 1997 .

[64]  Edmond P. F. Lee,et al.  Geometries and Binding Energies of Rg·NO+ Cationic Complexes (Rg = He, Ne, Ar, Kr, and Xe) , 1998 .

[65]  J. Toennies,et al.  Spectroscopy of atoms and molecules in liquid helium. , 1998, Annual review of physical chemistry.

[66]  M. Kolbuszewski,et al.  Adiabatic and strictly diabatic potential curves of He2+2 , 1995 .

[67]  G. T. Fraser,et al.  Current Themes in Microwave and Infrared Spectroscopy of Weakly Bound Complexes , 1994 .

[68]  Jonathan Tennyson,et al.  Predicted vibration-rotation levels of HeH2+ and its isotopomers , 1987 .

[69]  W. Kołos,et al.  Correlated Orbitals for the Ground State of the Hydrogen Molecule , 1960 .

[70]  P. Schwerdtfeger,et al.  Geometry optimization of triply charged yttrium-doped helium clusters: HenY3+ , 2002 .

[71]  C. W. Bauschlicher,et al.  Theoretical Study of the Low-Lying States of TiHe(+),TiNe(+),TiAr(+),VAr(+),CrHe(+),CrAr(+),FeHe(+),FeAr(+),CoHe(+),and CoAr(+) , 1994 .

[72]  N. Shimakura,et al.  LETTER TO THE EDITOR: One- and two-electron excitations in large angle scattering of Li+ ions from He atoms , 2002 .

[73]  E. W. McDaniel,et al.  The Li+–He interaction potential , 1977 .

[74]  J. Tennyson,et al.  Ab initio investigation of the bound rovibrational states in the electronic ground state of HeN+2 , 1988 .

[75]  H. Stoll,et al.  Helium chemistry of rare earth elements: Pseudopotential study of the cations LnHe3+ , 1991 .

[76]  G. Prakash,et al.  Helionitronium trication (NO2He3+) and helionitrosonium trication (HeNO3+). , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[77]  Paola Antoniotti,et al.  Stable Compounds of the Lightest Noble Gases: A Computational Investigation of RNBeNg (Ng = He, Ne, Ar) , 2003 .

[78]  O. Dopfer.  Spectroscopic and theoretical studies of CH+ 3-Rgn clusters (Rg=He, Ne, Ar): From weak intermolecular forces to chemical reaction mechanisms , 2003 .

[79]  S. Nizkorodov,et al.  Infrared predissociation spectra of He_HO2+ and Ne_HO2+: prediction of the gn1 frequency of HO2+ , 1997 .

[80]  F. Siu,et al.  Absolute potassium cation affinities (PCAs) in the gas phase. , 2003, Chemistry.

[81]  E. I. Nagy-Felsobuki,et al.  Ab initio investigations of the electronic structure of HeCH+ and HeCH2+ , 1997 .

[82]  J. Leszczynski,et al.  A Comprehensive Computational Study on OCH + -Rg (Rg = He, Ne, Ar, Kr, Xe) Complexes , 2003 .

[83]  Kanter,et al.  Direct determination of the stereochemical structure of CH4+ , 1986, Physical Review Letters.

[84]  P. Soldán,et al.  Near-dissociation states and coupled potential curves for the HeN+ complex , 2002 .

[85]  J. Cioslowski.  Endohedral magnetic shielding in fullerenes. A GIAO CPHF study , 1994 .

[86]  V. Aquilanti,et al.  Ab initio dynamics of the He + H+ 2 → HeH+ +H reaction: a new potential energy surface and quantum mechanical cross-sections , 2000 .

[87]  B. Liu,et al.  Dissociation Energies ofHe2+(X2Σu+)andHe2(A1Σu+) , 1971 .

[88]  A. Metropoulos,et al.  Adiabatic calculations of the 2Σ+g excited states of He+2 , 1987 .

[89]  P. Pyykkö,et al.  Two-dimensional, fully numerical molecular calculations: XI. Hartree-Fock results for BeH+, LiHe+, CH+, NeH+, C2, BeO, LiF, NaH, MgH+, HeNe, LiNa and F2 , 1987 .

[90]  Guberman.  Dissociative recombination without a curve crossing. , 1994, Physical review. A, Atomic, molecular, and optical physics.

[91]  E. Scifoni,et al.  Dynamical ionization of the 4He trimer: A time-dependent modeling of its fragmentation , 2003 .

[92]  Martin Saunders,et al.  Two helium atoms inside fullerenes: probing the internal magnetic field in C60(6-) and C70(6-). , 2002, Journal of the American Chemical Society.

[93]  G. Bent,et al.  AB INITIO (HEH2)+ ENERGY SURFACES AND NONADIABATIC COUPLINGS BETWEEN THEM , 1990 .

[94]  O. Dopfer,et al.  High-resolution spectroscopy of cluster ions. , 2000, Chemical reviews.

[95]  N. Kobayashi,et al.  Formation of Helium Cluster Ions 4Hen+ (n≤15) in a Liquid Helium Cooled Drift Tube , 1988 .

[96]  S. Evangelisti,et al.  Ab initio study of the ground-state potential of XH− anions (X=He,Ne,Ar) , 2001 .

[97]  M. Meuwly,et al.  The potential energy surface and near-dissociation states of He-H2+ , 1999 .

[98]  H. J. Oskam,et al.  Mass spectrometric proof of the existence of He+3 and He+4 ions , 1969 .

[99]  M. Meuwly,et al.  The ν3 infrared spectrum of the HeNH4+ complex , 1996 .

[100]  J. Elguero,et al.  How strong are the complexes between methane radical cation and noble gas atoms , 1999 .

[101]  K. Christe.  A Renaissance in Noble Gas Chemistry. , 2001, Angewandte Chemie.

[102]  Helmut Schwarz,et al.  The Neutralization of HeC in the Gas Phase: Compelling Evidence for the Existence of an Endohedral Structure for He@C60 , 1992 .

[103]  W. Breckenridge,et al.  Potential curves for several electronic states of the MgHe, Mg+He, and Mg+2He van der Waals complexes , 1999 .

[104]  P. L. Patterson.  Evidence of the Existence of an He3+ Ion , 1968 .

[105]  D. L. Cooper,et al.  Abinitio calculation of molecular spin‐orbit coupling constants using a universal even‐tempered basis set of exponential functions , 1982 .

[106]  Sudarko,et al.  Ab Initio Rotational and Rovibrational Transitions and Linestrengths of He2N2 , 2001 .

[107]  L. Viehland,et al.  Transport properties for systems with resonant charge transfer , 1986 .

[108]  O. Dopfer,et al.  Intermolecular interaction in proton-bound dimers.: Infrared photodissociation spectra of Rg–HOCO+ (Rg=He, Ne, Ar) complexes , 1998 .

[109]  Rosner,et al.  Mean lifetime measurements of HeH2+(2p sigma ) isotopes. , 1996, Physical review. A, Atomic, molecular, and optical physics.

[110]  W. Breckenridge,et al.  An ab initio study of the ground states and some excited states of BeRG, Be+RG, and Be+2RG van der Waals complexes (RG=He, Ne) , 1999 .

[111]  Wolfram Koch,et al.  Stabilities and nature of the attractive interactions in HeBeO, NeBeO, and ArBeO and a comparison with analogs NGLiF, NGBN, and NGLiH (NG = He, Ar). A theoretical investigation , 1988 .

[112]  J. Ackermann,et al.  Adiabatic calculations and properties of the He2+ molecular ion , 1991 .

[113]  D. Ceperley,et al.  The dissociation energy of He2 , 1989 .

[114]  H. Skullerud,et al.  Diffusion and interaction potentials for K+ ions in the noble gases , 1999 .

[115]  I. Ben-Itzhak,et al.  Experimental evidence for long-lived HeAr2+ rare-gas dimers , 1999 .

[116]  Neil Bartlett,et al.  Concerning the nature of XePtF6 , 2000 .

[117]  E. Davidson,et al.  The potential energy surfaces of He2+: implications for femtosecond spectroscopy , 1997 .

[118]  J. Toennies,et al.  Absorption spectroscopy and photodissociation dynamics of small helium cluster ions , 1995 .

[119]  A. Viggiano,et al.  Reactions of Mass-Selected Cluster Ions in a Thermal Bath Gas , 1998 .

[120]  Hiroshi Sato,et al.  Accurate electronic energies of He ++ 2 , 1977 .

[121]  K. Krogh-Jespersen,et al.  Why Do Cationic Carbon Monoxide Complexes Have High C−O Stretching Force Constants and Short C−O Bonds? Electrostatic Effects, Not σ-Bonding , 1996 .

[122]  E. I. Nagy-Felsobuki,et al.  Ab initio calculations of the rovibrational states of He2O2 , 1997 .

[123]  M. Meuwly,et al.  Vibrational states in the electronic ground state of the OH+–He and OH+–Ne complexes , 1998 .

[124]  Alexander Dalgarno,et al.  The mobilities of ions in unlike gases , 1958, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[125]  K. Yamashita,et al.  Theoretical study on the structure of Na+-doped helium clusters: Path integral Monte Carlo calculations , 2000 .

[126]  N. Handy,et al.  The diagonal born-oppenheimer correction for He2+ and F+H2 , 1996 .

[127]  S. Nizkorodov,et al.  Metastable decay of N+2Hen (υ = 1) (1 < n⩽6) clusters , 1994 .

[128]  J. F. Liebman,et al.  Salt chemistry of light noble gas compounds , 1970 .

[129]  J. E. Russell,et al.  Analysis of the reaction He++He+He→He+2+He. III. Effects of resonant quasibound states , 1989 .

[130]  A. Dalgarno,et al.  The formation and destruction of HeH/+/ in astrophysical plasmas , 1982 .

[131]  F. Fehsenfeld,et al.  Flowing Afterglow Measurements of Ion-Neutral Reactions , 1969 .

[132]  L. Radom,et al.  Helides of carbon and silicon: an ab initio study of their geometric and electronic structures , 1992 .

[133]  J. Kendrick,et al.  Practical application of extended valence bond diatomic calculations to the method of diatomics‐in‐molecules for NeHe+2 , 1979 .

[134]  V. Staemmler.  Ab initio study of small He cluster ions Hen+,n=2, 3, 4, 5, and low-lying Rydberg states of He4 , 1990 .

[135]  C. Jameson,et al.  Calculation of the 129Xe chemical shift in Xe@C60 , 2003 .

[136]  L. Viehland,et al.  The mobility of He+ ions in helium gas , 1999 .

[137]  F. Smith,et al.  COLLISION SPECTROSCOPY. IV. SEMICLASSICAL THEORY OF INELASTIC SCATTERING WITH APPLICATIONS TO He$sup +$ + Ne. , 1971 .

[138]  Edward A. Mason,et al.  Mobility of gaseous lons in weak electric fields , 1958 .

[139]  P. Knowles,et al.  Microwave electronic spectrum of the He+2 ion , 1995 .

[140]  Mitchell,et al.  Recombination and excitation of HeH+ , 1989, Physical review. A, General physics.

[141]  C. Marsden,et al.  Ab Initio Structures and Stabilities of Doubly Charged Diatomic Metal Helides for the First Row Transition Metals , 2002 .

[142]  J. Browne.  Some Excited States of He++2 : Mixed Basis-Set Calculations , 1965 .

[143]  J. Toennies,et al.  Superfluidity within a small helium-4 cluster: the microscopic andronikashvili experiment , 1998, Science.

[144]  F. Gianturco,et al.  Stability and structure of rare-gas ionic clusters using density functional methods: A study of helium clusters , 1996 .

[145]  Wolfram Koch,et al.  Light noble gas chemistry: structures, stabilities, and bonding of helium, neon, and argon compounds , 1990 .

[146]  G. I. Gellene,et al.  Ab initio QCISD(T) calculations of the ground potential energy surface of He3 , 1995 .

[147]  Weedon,et al.  3He NMR study of (3)He@C(60)H(6) and (3)He@C(70)H(2)(-)(10) , 2000, Organic letters.

[148]  V. A. Apkarian,et al.  Charge localization and fragmentation dynamics of ionized helium clusters , 1998 .

[149]  T. Mārk,et al.  Laser-induced photodissociation of He+2 , 1980 .

[150]  F. Naumkin,et al.  On the influence of rare gas atom–chlorine ion potentials on the ground state Rg–Cl2 interactions , 1998 .

[151]  Andreas Hirsch,et al.  Spherical Aromaticity in Ih Symmetrical Fullerenes: The 2(N+1)2 Rule. , 2000, Angewandte Chemie.

[152]  E. Campbell,et al.  Capture dynamics in collisions between fullerene ions and rare gas atoms , 1998 .

[153]  S. Miret-Artés,et al.  Computed energy curves for modelling the dissociation of helium trimer ions , 1996 .

[154]  K. Killeen,et al.  Gerade Rydberg states and ns 3Σ+u(1u,0−u) photoionization spectra of the rare gas dimers (n=2–6) , 1986 .

[155]  G. Kyrala,et al.  Observation of the Infrared Spectrum of the Helium-Hydride Molecular Ion ^{4}HeH^{+} , 1979 .

[156]  P. Aped,et al.  Valence bond energy curves for He22 , 1996 .

[157]  T. R. Hogness,et al.  The Ionization of Hydrogen by Electron Impact as Interpreted by Positive Ray Analysis , 1925 .

[158]  È. Roueff,et al.  Depolarization, broadening and shift of Sr II and Ca II lines by helium atoms , 1975 .

[159]  K. Janda,et al.  Fragmentation of ionized liquid helium droplets: A new interpretation , 1998 .

[160]  E. I. Nagy-Felsobuki,et al.  Ab initio calculations of the rovibrational states of He2N2 , 1996 .

[161]  M. Saunders,et al.  Probing the interior of fullerenes by 3He NMR spectroscopy of endohedral 3He@C60 and 3He@C70 , 1994, Nature.

[162]  T. Tsong,et al.  Pulsed-Laser Atom-Probe FIM Study of Solid Surfaces , 1983 .

[163]  N. Kobayashi,et al.  Formation of helium cluster ions HHex+ (x≦14) and H3Hex+ (x≦13) in a very low temperature drift tube , 1992 .

[164]  F. Matsushima,et al.  Observation of the Rotational Spectra of 4 HeH + , 4 HeD + , 3 HeH + , and 3 HeD + , 1997 .

[165]  P. C. Hariharan,et al.  Potential energy curve of 1Σ+ Li+/He , 1976 .

[166]  S. Peyerimhoff,et al.  Ab initio calculation of the X2Σ+u state of He+2 and adjustment governed by translational spectroscopic measurements , 1976 .

[167]  D. Clary,et al.  A method to calculate vibrational frequency shifts in heteroclusters: application to N2+–Hen , 1996 .

[168]  Hajigeorgiou,et al.  Experimental Born-Oppenheimer Potential for the X1Sigma+ Ground State of HeH+: Comparison with the Ab Initio Potential. , 1999, Journal of molecular spectroscopy.

[169]  J. Tennyson,et al.  Dissociative recombination without curve crossing: study of HeH+ , 1994 .

[170]  J. Seong,et al.  HeNe + : resolution of an apparent disagreement between experiment and theory , 1999 .

[171]  C. Bauschlicher,et al.  Theoretical study of metal ions bound to He, Ne, and Ar , 1992 .

[172]  M. Speranza.  Tritium for generation of carbocations , 1993 .

[173]  K. Szalewicz,et al.  Dispersion Energy in the Coupled Pair Approximation with Noniterative Inclusion of Single and Triple Excitations , 1995 .

[174]  F. Gadéa,et al.  Ab initio calculations for Ar2+, He2+ and He3+, of interest for the modelling of ionic rare-gas clusters , 1996 .

[175]  F. Filippone,et al.  Competitive shell-filling in protonated helium clusters , 1999 .

[176]  E. Müller,et al.  Field Adsorption of Inert-Gas Atoms on Field Ion Emitter Surfaces , 1970 .

[177]  P. Larsen,et al.  Mobility and diffusion of atomic helium and neon ions in their parent gases , 1990 .

[178]  M. J. Dorko,et al.  Ab initio/spectroscopic interaction potential for He+Ne+ , 2000 .

[179]  G. I. Gellene,et al.  A quantum dynamical study of the He++2He→He2++He reaction , 2003 .

[180]  T. Clark,et al.  Nature of the interaction of paramagnetic atoms (A=4N,4P,3O,3S) with π systems and C60: A theoretical investigation of A⋅⋅⋅C6H6 and endohedral fullerenes A@C60 , 2002 .

[181]  Michael Mautner,et al.  The ionic hydrogen bond and ion solvation. 1. NH+.cntdot..cntdot..cntdot.O, NH+.cntdot..cntdot..cntdot.N, and OH+.cntdot..cntdot..cntdot.O bonds. Correlations with proton affinity. Deviations due to structural effects , 1984 .

[182]  E. Müller,et al.  Field Adsorption of Inert‐Gas Atoms , 1971 .

[183]  G. Herzberg,et al.  The Spectrum of HeNe , 1978 .

[184]  Kiyoshi Tanaka,et al.  The interaction potentials for He-He and He-Li+ , 1984 .

[185]  S. Seidel,et al.  Xenon as a Complex Ligand: The Tetra Xenono Gold(II) Cation in AuXe4 , 2000 .

[186]  B. Žemva,et al.  New coordination compounds of Cd(AsF6)2 with HF and XeF2. , 2004, Inorganic chemistry.

[187]  D. Bohme,et al.  Reactions of He2+, Ne2+, Ar2+, and Rare‐Gas Hydride Ions with Hydrogen at 200°K , 1970 .

[188]  F. Gianturco,et al.  Charged chromophoric units in protonated rare-gas clusters: A dynamical simulation , 1998 .

[189]  C. Bauschlicher,et al.  On the binding energy of He(n)+, for n = 2-7 , 1989 .

[190]  R. Zahradník,et al.  Reactions between H+3 and rare gas atoms , 1993 .

[191]  M. Saunders,et al.  The 3He NMR spectra of a [60]fullerene cation and some arylated [60]fullerenes , 1999 .

[192]  F. H. Field,et al.  High‐Pressure Mass Spectrometric Study of Reactions of Rare Gases with N2 and CO , 1962 .

[193]  O. Dopfer,et al.  Microsolvation of the Phenol Cation (Ph+) in Nonpolar Environments: Infrared Spectra of Ph+−Ln (L = He, Ne, Ar, N2, CH4)† , 2001 .

[194]  M. Meuwly.  The potential energy surface and rovibrational states of He–HCO+ , 1999 .

[195]  J. Bardsley.  Configuration interaction in the continuum states of molecules , 1968 .

[196]  J. Toennies,et al.  Electron capture by large helium droplets , 1998 .

[197]  L. Massa,et al.  Ion-induced dipole clusters: Be2+He2 , 1972 .

[198]  L. Viehland,et al.  Transport coefficients for NO+ ions in helium gas: a test of the NO+He interaction potential , 1996 .

[199]  W. E. Billups,et al.  Formation, isolation, spectroscopic properties, and calculated properties of some isomers of C(60)H(36). , 2001, Journal of the American Chemical Society.

[200]  Linus Pauling,et al.  The Normal State of the Helium Molecule-Ions He 2 + and He 2 ++ , 1933 .

[201]  J. T. Hougen,et al.  An interesting example of Hund's coupling case (c) in HgAr+ , 1972 .

[202]  S. Barlow,et al.  Reactions of H2 with He+ at temperatures below 40 K , 1989 .

[203]  Jun Yu Li,et al.  Noble gas-actinide complexes of the CUO molecule with multiple Ar, Kr, and Xe atoms in noble-gas matrices. , 2003, Journal of the American Chemical Society.

[204]  K. Hardy,et al.  First Measurement of the Rotational Constants for the Homonuclear Molecular Ion He + 2 , 1999 .

[205]  B. Maiti,et al.  Reaction probabilities and reaction cross sections for three-dimensional He+H2+(v) collisions: A time-dependent quantum mechanical study , 2002 .

[206]  M. Meuwly,et al.  Reply to the comment on “The ν3 infrared spectrum of the HeNH4+ complex” , 1997 .

[207]  W. Eisfeld,et al.  Are helionitronium trications stable? , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[208]  M. Gross,et al.  Endohedral Complexes of Fullerene Radical Cations , 1991 .

[209]  S. Wexler,et al.  Isomeric Effects in Fragmentation by Beta Decay: Monotritiated Propanes and Toluenes , 1960 .

[210]  C. Deakyne,et al.  Noble gas compounds and chemistry: a brief review of interrelations and interactions with fluorine-containing species , 2003 .

[211]  Frederick Albert Matsen IV,et al.  New Lower Limit for the Binding Energy of the Helium Molecule Ion , 1962 .

[212]  E. I. Nagy-Felsobuki,et al.  Ab Initio investigation of the electronic structure and stabilities of triatomic helide ions: He2Xn+ clusters (where X=B–Ne, Al–Ar and n=1–2) , 1999 .

[213]  O. Dopfer,et al.  Intermolecular potential energy surface of the proton-bound H2O+–He dimer: Ab initio calculations and IR spectra of the O–H stretch vibrations , 2001 .

[214]  E. Lankester.  Pliocene and Pleistocene , 1925, Nature.

[215]  D. Luckhaus,et al.  Rovibrational calculations for CH3+–Rg (Rg=He,Ne): The prototype disk-and-ball dimer , 2002 .

[216]  P. Knowles,et al.  Towards reliable modelling of large clusters: on the overall accuracy of the diatomics-in-molecule method for rare gas cluster ions , 1995 .

[217]  P. Pyykkoe.  Predicted Chemical Bonds between Rare Gases and Au , 1995 .

[218]  J. Leszczynski,et al.  Post‐Hartree–Fock study on Ar–HCO+ and He–HCO+ complexes: A critical examination of experimental data , 1996 .

[219]  E. A. Mason,et al.  Ion Mobilities with Charge Exchange , 1970 .

[220]  Wojciech Cencek,et al.  Benchmark calculations for He2+ and LiH molecules using explicitly correlated Gaussian functions , 2000 .

[221]  P. Archirel.  Preoptimised VB: a fast method for the ground and excited states of ionic clusters II. Delocalised preoptimisation for He2+, Ar2+, He3+ and Ar3+☆ , 1997 .

[222]  N. Adams,et al.  Theoretical calculations of the HeB+ molecular ion interaction potential and the mobility of B+ ions in helium , 1989 .

[223]  R. A. Kennedy,et al.  Infrared bound to quasibound vibration-rotation spectrum of HeH+ and its isotopes , 1983 .

[224]  D. S. Ginter,et al.  Spectrum and Structure of the He2 Molecule. V. Characterization of the Triplet States Associated with the UAO's 6− 17pπ and 7− 12pσ , 1968 .

[225]  P. Španěl,et al.  Studies of interstellar ion reactions using the SIFT technique: isotope fractionation , 1992 .

[226]  D. Cremer,et al.  The chemistry of the noble gas elements helium, neon, and argon — Experimental facts and theoretical predictions , 1990 .

[227]  P. Siska,et al.  Theoretical study of ion–molecule potentials for He+ and Li+ with N2 , 1998 .

[228]  E. Ferguson,et al.  Measurement of the equilibrium constant of the reaction HeH+ + Ne ⇌ NeH+ + He in a selected ion flow tube , 1991 .

[229]  H. Hidaka,et al.  Mobility of NO+ in helium gas at 77 and 4.3 K , 2003 .

[230]  J. Peek,et al.  New ab initio potential curve and quasibound states of HeH , 1976 .

[231]  Kim,et al.  Electron attachment to helium microdroplets: Creation induced magic? , 1993, Physical review letters.

[232]  L. Radom,et al.  Multiply-charged cations: remarkable structures and stabilities , 1988 .

[233]  D. Liao,et al.  Simulation study of the formation mechanisms of endohedral C60 by atomic collisions , 1994 .

[234]  W. J. Meath,et al.  The rotating wave approximation, including the incorporation and importance of diagonal dipole moment matrix elements, for infrared multiphoton excitations , 1992 .

[235]  V. Špirko,et al.  Ab Initio Predicted Rotation-Vibration Energy Levels of HeH+2 , 1995 .

[236]  G. Frenking,et al.  The singlet-triplet splitting of the low-lying electronic states of H2O2+ and a comparison with isoelectronic CH2 and CH22+ , 1987 .

[237]  F. Gianturco,et al.  Some properties of the lower electronic states for nonlinear He3+ clusters , 1997 .

[238]  J. Simons,et al.  Potential energy curves of M(np 2P)⋅RG(2Π) excited states and M+⋅RG ground states (M=Li, Na; RG=He, Ne) , 1994 .

[239]  W. Breckenridge,et al.  The effects of dispersive Cn/Rn-attraction on M+/Rg bonding (M+=atomic metal ion, Rg=rare gas atom) , 2001 .

[240]  K. Janda,et al.  Capture and ionization of argon within liquid helium droplets , 1998 .

[241]  R. Blint.  Potential energy curves for the collisional excitation of the (HeNe) + system , 1976 .

[242]  Ioannis S. K. Kerkines,et al.  On the Bonding Nature of the N5+(=N(N2)2+) Cation and Related Species N(CO)x+, N(NH3)x+, and NRx+, x = 1, 2 and R = He, Ne, Ar, Kr. Do We Really Need the Resonance Concept? , 2002 .

[243]  L. Wolniewicz.  Accurate adiabatic potentials of the two lowest 1Sigmag states of He2+2 , 1999 .

[244]  L. Massa,et al.  He–Be2+ interaction energy at small internuclear distances , 1973 .

[245]  S. Nizkorodov,et al.  The infrared spectrum of He–HCO+ , 1995 .

[246]  M. Elford,et al.  The interatomic potential for the state of , 1996 .

[247]  R. Gerber,et al.  He$sub 3$$sup +$ AND He$sub 4$$sup +$ IN 300$sup 0$K HELIUM PLASMAS: THEIR EFFECT ON RECOMBINATION LOSS OF ELECTRONS. , 1970 .

[248]  P. Siska.  A modified Tang–Toennies model for ion–atom potential curves , 1986 .

[249]  A. Avoird,et al.  Method for the ab initio calculation of intermolecular potentials of ionic clusters: Test on Rg–CO+, Rg=He, Ne, Ar , 2003 .

[250]  M. Meuwly,et al.  Mid‐infrared spectra of He–HN+2 and He2–HN+2 , 1996 .

[251]  A. S. Dickinson.  The mobility of He+ ions in He , 1968 .

[252]  M. Coggiola,et al.  Mass spectrometric observation of carbon-helium ions , 1986 .

[253]  A. C. Wahl,et al.  Interaction Energy Curves of LiHe and NaHe (X 2Σ+, A 2Π, B 2Σ+) and X 1Σ+ Ions , 1971 .

[254]  Stephen Wilson,et al.  Theoretical studies of the HeCN+ and NeCN+ molecular ions , 1980 .

[255]  J. Ackermann,et al.  On the metastability of the 1 Sigma +g ground state of He2+2 and Ne2+2: a case study of binding metamorphosis , 1992 .

[256]  E. Müller,et al.  Field Evaporation of Tungsten-Helium Molecular Ions , 1973 .

[257]  M. Saunders,et al.  The inside story of fullerene anions: a 3He NMR aromaticity probe. , 2003, Angewandte Chemie.

[258]  J. Gaudet.  Marsilea vestita: Conversion of the Water Form to the Land Form by Darkness and by Far-Red Light , 1963, Science.

[259]  S. Sinha,et al.  The mobility of He+ ions in He , 1979 .

[260]  J. Seong,et al.  Short-time charge motion in Hen+ clusters , 1998 .

[261]  H. Böhm,et al.  Interaction potentials for alkali ion–rare gas and halogen ion–rare gas systems , 1988 .

[262]  C. Marsden,et al.  Ab initio structures and stabilities of HeTM3+ (TM=Sc–Cu) , 2002 .

[263]  P. Davies,et al.  Infrared laser absorption spectroscopy of rotational and vibration rotational transitions of HeH+ up to the dissociation threshold , 1997 .

[264]  A. Thakkar,et al.  Interaction potentials for He–F− and Ne–F− , 1998 .

[265]  Yong Kiel Sung,et al.  The atom-atom potential. Exohedral and endohedral complexation energies of complexes of X@C60 between fullerene and rare-gas atoms (X = He, Ne, Ar, Kr, and Xe) , 1995 .

[266]  J. Rychlewski,et al.  Many‐electron explicitly correlated Gaussian functions. II. Ground state of the helium molecular ion He+2 , 1995 .

[267]  H. Hogreve.  Quartet states of He+ 2 , 2000 .

[268]  G. Olah,et al.  Heliomethonium dication, CH4He2+ , 1999 .

[269]  D. Thompson,et al.  Ground‐ and lower excited‐state discrete abinitio electronic potential‐energy surfaces for doublet HeH2+a) , 1979 .

[270]  E. F. Hayes,et al.  Theoretical Studies of Metal Ion (Be+2)—Rare Gas (He, Ne) Interactions: Possible Implications for Matrix Isolation Spectroscopy , 1971 .

[271]  R. Johnsen,et al.  Three‐body association reactions of He+, Ne+, and Ar+ ions in their parent gases from 78 to 300 K , 1980 .

[272]  Michael L. Gross,et al.  High-energy collisions of fullerene radical cations with target gases: capture of the target gas and charge stripping of C60.bul.+, C70.bul.+, and C84.bul.+ , 1992 .

[273]  B. Jursic.  Can CH cations and nobel gases form stable chemical systems? The density functional theory and ab initio studies of the stability of CHHe+ and CHHe2+ , 1998 .

[274]  R. D. Poshusta,et al.  Geometry and Binding Energy of He3 , 1968 .

[275]  P. Siska,et al.  Ab initio study of the long-range interaction between He+ and H2 , 1993 .

[276]  L. Reatto,et al.  Pure and alkali–ion-doped droplets of 4He , 2001 .

[277]  M. Bowers,et al.  Transition-metal ion-rare gas clusters : bond strengths and molecular parameters for Co+(He/Ne)n, Ni+(He/Ne)n, and Cr+(He/Ne/Ar) , 1991 .

[278]  D. L. Cooper,et al.  Spin-coupled valence bond study of low-lying states of LiHe+ , 1985 .

[279]  V. Sidis,et al.  A 'quasi-diabatic' representation for inelastic collisions Application to the scattering of He+ by Ne , 1971 .

[280]  M. Grüning,et al.  The failure of generalized gradient approximations (GGAs) and meta-GGAs for the two-center three-electron bonds in He-2(+), (H2O)(2)(+), and (NH3)(2)(+) , 2001 .

[281]  S. Petrie.  Model chemistry methods for molecular dications: The magnesium dication affinity scale , 2002 .

[282]  S. Nizkorodov,et al.  Intermolecular interaction in the CH3+–He ionic complex revealed by ab initio calculations and infrared photodissociation spectroscopy , 1999 .

[283]  N. F. Lane,et al.  Exact eigenvalues, electronic wavefunctions and their derivatives with respect to the internuclear separation for the lowest 20 states of the HeH2+ molecule , 1977 .

[284]  Jena,et al.  Interaction of H2 and He with metal atoms, clusters, and ions. , 1995, Physical review. B, Condensed matter.

[285]  J. Maier,et al.  Electronic spectra of N+2–(He)n (n=1, 2, 3) , 1992 .

[286]  J. Beynon,et al.  He22+, the experimental detection of a remarkable molecule , 1985 .

[287]  D. Bohme,et al.  Ab initio MO calculation on the energy barrier for the penetration of a benzene ring by a helium atom. Model studies for the formation of endohedral He@C60+ complexes by high-energy bimolecular reactions , 1992 .

[288]  A. Hirsch,et al.  Spherical aromaticity of fullerenes. , 2001, Chemical reviews.

[289]  C. Marsden,et al.  Ab initio calculations on first row transition metal hydrides TMHn+ and helides TMHe(n+1)+(TM = Sc–Cu, n = 0–2) , 2003 .

[290]  J. Murrell,et al.  Collision dynamics for small helium cluster ions , 1996 .

[291]  A. H. Snell,et al.  The Atomic and Molecular Consequences of Radioactive Decay , 1958 .

[292]  O. Dopfer,et al.  INFRARED SPECTRUM AND AB INITIO CALCULATIONS OF THE HE-HNH+ OPEN-SHELL IONIC COMPLEX , 1999 .

[293]  P. Wormer,et al.  Theoretical study of the He-HF+ complex. I. The two asymptotically degenerate ground state potential energy surfaces. , 2004, The Journal of chemical physics.

[294]  R. Buenker,et al.  Potential curves and nonadiabatic matrix elements for collisions involving fragments of the HeN+ molecular ion , 1995 .

[295]  B. Roos,et al.  On bonding in transition-metal helide ions , 1984 .

[296]  Edmond P. F. Lee,et al.  Spectroscopy of Na⁺．Rg and transport coefficients of Na⁺ in Rg(Rg＝He ―Rn) , 2003 .

[297]  M. Falcetta.  The long-range interaction between He and H+2: an ab initio and dynamical study , 1996 .

[298]  Edmond P. F. Lee,et al.  High-quality interatomic potential for Li + ·He , 2001 .

[299]  K. Noda,et al.  LETTER TO THE EDITOR: Dissociative recombination of ? isotopes with an ultra-cold electron beam from a superconducting electron cooler in a storage ring , 1998 .

[300]  Ab initio study of He2H+ and Ne2H+: Accurate structure and energetics , 1999 .

[301]  G. Herzberg.  Molecular Spectra and Molecular Structure IV. Constants of Diatomic Molecules , 1939 .

[302]  E. Müller,et al.  Field adsorption and desorption of helium and neon , 1969 .

[303]  E. S. Chang,et al.  Elastic scattering of Li+ by He , 1970 .

[304]  Li Bai-wen,et al.  Calculations of Electron Structure of Endohedrally Confined Helium Atom with B-Spline Type Functions , 2002 .

[305]  J. M. Hughes,et al.  Ab initio structures and stabilities of helide cations: (X = B-Ne, Al-Ar and n = 1-3) , 1987 .

[306]  E. A. Mason,et al.  Charge-transfer energy in closed-shell ion-atom interactions. [for H and Li ions in He , 1975 .

[307]  Helmut Schwarz,et al.  Sequential Insertion of 3He and 4He in C 60 , 1992 .

[308]  A. Jalbout,et al.  Density functional theory analysis of CaRgn+ complexes: (Rg=He, Ne, Ar; n=1–4) , 2003 .

[309]  S. Borocci,et al.  SBeNg, SBNg+, and SCNg2+ complexes (Ng=He, Ne, Ar): a computational investigation on the structure and stability , 2004 .

[310]  B. Lévy,et al.  Potential energy curves of (HeNe)2+. Electronic couplings and transition dipole moment calculations , 1985 .

[311]  W. Breckenridge,et al.  M+/Rg bonding: The effects of M+ permanent quadrupole moments (M+= atomic metal ion; Rg=rare gas atom) , 2001 .

[312]  Edmond P. F. Lee,et al.  The intermolecular potential energy surface of the He．NO⁺ cationic complex , 2002 .

[313]  C. E. Blom,et al.  Diode laser spectra and potential energy curve for the molecular ion HeH , 1992 .

[314]  O. Tüxen.  Massenspektrographische Untersuchungen negativer Ionen in Gasentladungen bei höheren Drucken , 1936 .

[315]  R. A. Kennedy,et al.  Observation of bound to quasibound vibration-rotation transitions in the HeH+ ion , 1981 .

[316]  D. Hausamann,et al.  The heteronuclear rare gas ions , 1985 .

[317]  O. Dopfer,et al.  Spectroscopic and ab initio studies of ionic hydrogen bonds: the O–H stretch vibration of SiOH+–X dimers (X=He, Ne, Ar, N2) , 1999 .

[318]  I. H. Hillier,et al.  Ab initio calculation of the potential energy surface and cross sections for the reactions Ne+2 + He → NeHe+ + Ne and Ne+2 + Ne + He , 1979 .

[319]  Eugene D. Fleischmann,et al.  Endohedral complexes: Atoms and ions inside the C60 cage , 1991 .

[320]  H. Tanuma,et al.  Formation of Helium Cluster Ions N 2Hen+, COHen+, and O 2Hen+ (n ≤ 13) in Cooled Helium Gas , 1999 .

[321]  M. Saunders,et al.  3HE NMR : A POWERFUL NEW TOOL FOR FOLLOWING FULLERENE CHEMISTRY , 1994 .

[322]  Jan Lundell,et al.  A stable argon compound , 2000, Nature.

[323]  J. Murrell,et al.  The structures and stabilities of mixed inert gas cluster ions: NeHe+ n and ArHe+ n , 2001 .

[324]  A. Rohrbacher,et al.  Potential energy surfaces for HenNe+ ions: ab initio and diatomics-in-molecule results. , 2004, The Journal of chemical physics.

[325]  F. Paesani,et al.  Structural properties and quantum effects in protonated helium clusters. II. Quantum Monte Carlo calculations for the smaller aggregates , 2000 .

[326]  R. Olson,et al.  Electron detachment in Br − +He collisions: Potential energies for Br He − and BrHe , 1979 .

[327]  Helmut Schwarz,et al.  Endohedral Cluster Compounds: Inclusion of Helium within C 60•⊕ and C 70•⊕ through Collision Experiments , 1991 .

[328]  R. Cimiraglia,et al.  The determination of radial non-adiabatic coupling: HeNe2+ as a case study , 1984 .

[329]  S. Iwata,et al.  Ab initio studies of the β−‐decay in OHT, NH2T, CH3T, and 14CH4 , 1977 .

[330]  L. Viehland.  Interaction potentials for Li+—rare-gas systems , 1983 .

[331]  Tien T. Tsong,et al.  Field ion microscopy, field ionization and field evaporation , 1974 .

[332]  E. I. Nagy-Felsobuki,et al.  THEORETICAL INVESTIGATIONS OF THE ELECTRONIC STRUCTURE OF HEHO+ AND HEHO2+ , 1997 .

[333]  J. Callahan,et al.  Formation and characterization of carbon mol.-helium (C60He+) , 1991 .

[334]  Cleanthes A. Nicolaides,et al.  Energy generation from volcanic ground states. Application to cold He22 , 1989 .

[335]  H. Schwarz,et al.  Injection of helium atoms into doubly and triply charged carbon (C60) cations , 1991 .

[336]  R. R. Filgueira,et al.  Gas discharge modulation using fast electronic switches: application to HeH+ , 1987 .

[337]  J. Ackermann,et al.  A CI study of the ground state potential energy surface of He+ 3 , 1989 .

[338]  E. Campbell,et al.  Collision energy dependence of He and Ne capture by C60+ , 1992 .

[339]  Wei Zhou,et al.  A theoretical study of markovnikov and anti-markovnikov protonation of olefines by HeH+ , 1991 .

[340]  D. M. Bishop,et al.  A theoretical investigation of HeH , 1979 .

[341]  A. Sapse,et al.  A Theoretical Study of LiHe+n, NaHe+n, and MgHe+n Complexes, with n=1, 2, 3, 4 , 2003 .

[342]  Frederick Albert Matsen IV,et al.  Potential Curves for the X2Σu+ and the Lowest 2Σg+ States of the Helium Molecule Ion , 1967 .

[343]  S. Bobbio,et al.  Curve crossing for low-energy elastic scattering of He/+/ by Ne. , 1973 .

[344]  G. Herzberg,et al.  The spectrum of HeAr , 1981 .

[345]  The chemistry of the early Universe , 1998, astro-ph/9803315.

[346]  E. Campbell,et al.  He capture by negatively charged Buckminsterfullerene , 1993 .

[347]  P. Pyykkö.  Ab initio study of bonding trends among the sulphur-containing 16-valence-electron ABC species: SBO−, SBS−, SNO+ and SXNen , 1989 .

[348]  F. Cacace.  Gaseous Carbonium Ions from the Decay of Tritiated Molecules , 1970 .

[349]  C. Gaussorgues.  Differential scattering cross section for excitation in He+Ne collisions , 1973 .

[350]  J. Gauss,et al.  Helium bonding in singly and doubly charged first-row diatomic cations HeXn+ (X = Li-Ne; n = 1,2) , 1989 .

[351]  Edmond P. F. Lee.  Accurate adiabatic energy surfaces for the ground and first excited states of He+2 , 1993 .

[352]  V. A. Apkarian,et al.  CHARGE TRANSFER WITHIN HE CLUSTERS , 1996 .

[353]  O. Bludský,et al.  Bound and low-lying quasi-bound rotation-vibration energy levels of the ground and first excited electronic states of HeH2+ , 2002 .

[354]  C. Girardet,et al.  Structure of the Van der Waals rare gas–C60 exohedral complexes [(C60)(RG)n; n=1, 2] , 1998 .

[355]  J. Beynon,et al.  First observation of He22+: charge stripping of He2+ using a double-focusing mass spectrometer , 1984 .

[356]  M. Elford,et al.  The mobility of potassium ions in helium , 1996 .

[357]  M. Meuwly,et al.  The N2H+–He intermolecular potential energy surface: A vibrational adiabatic correction , 1997 .

[358]  A. M. Shaw,et al.  Observation of a microwave spectrum of the long-range He…N+ complex , 1996 .

[359]  E. Shipsey,et al.  Direct and charge exchange inelastic processes in ion-atom collisions. II. He+-Ne , 1976 .

[360]  P. Burton,et al.  A CEPA2 investigation of the He-He and He-Li+ potential functions , 1986 .

[361]  P. Knowles,et al.  AN N-VALUED REPRESENTATION OF HE+N POTENTIALS , 1995 .

[362]  Jae Shin Lee,et al.  A calculation of the rotation–vibration states of He2H+ , 1986 .

[363]  Rosner,et al.  Experimental evidence for the existence of the 2p sigma bound state of HeH2+ and its decay mechanism. , 1993, Physical review letters.

[364]  P. Knowles,et al.  The metastable quartet state of He+4 , 1995 .

[365]  G. Scuseria,et al.  Theoretical Evidence for a C60 "Window" Mechanism , 1994, Science.

[366]  P. Pyykkö.  Ab initio study of bonding trends among the 14-electron diatomic systems: from B2 4- to F2 4+ , 1989 .

[367]  H. Bohringer,et al.  Temperature dependence of the mobility and association rate coefficient of He+ ions in He from 30-350K , 1983 .

[368]  E. Ferguson,et al.  The role of electron transfer stabilization in several gas phase ion–molecule reaction processes , 1987 .

[369]  S. Nizkorodov,et al.  Intermolecular interaction in the OH+–He and OH+–Ne open-shell ionic complexes: Infrared predissociation spectra of the ν1 and ν1+νb vibrations , 1998 .

[370]  S. Koch,et al.  Mean lifetime measurements and calculations of long-lived HeNe2+ isotopes , 1997 .

[371]  G. I. Gellene,et al.  An ab initio, analytically fitted, global potential energy surface for the ground electronic state of He3+ , 2003 .

[372]  P. Pyykko.  CHEMISTRY: Noblesse Oblige , 2000 .

[373]  M. Beyer,et al.  Proton solvated by noble-gas atoms: simplest case of a solvated ion , 1999 .

[374]  J. Gspann.  Negatively charged helium-4 clusters , 1991 .

[375]  A. M. Shaw,et al.  Microwave spectroscopy and interaction potential of the long‐range He⋯Kr+ ion: An example of Hund’s case (e) , 1996 .

[376]  N. Bacalis,et al.  Theory for the direct construction of diabatic states and application to the He+22Σ+g spectrum , 1992 .

[377]  J. Toennies,et al.  Superfluid helium droplets: a uniquely cold nanomatrix for molecules and molecular complexes. , 2004, Angewandte Chemie.

[378]  N. Bacalis.  Existence of He2- negative ions with two remote electrons in antibonding orbitals , 2000 .

[379]  B. Balta,et al.  Structural properties and quantum effects in protonated helium clusters. I. The ab initio interaction potential , 2000 .

[380]  V. Kresin,et al.  Capture of lithium by 4He clusters: Surface adsorption, Penning ionization, and formation of HeLi+ , 1997 .

[381]  A. Hirsch,et al.  High-energy collisions of organofullerene cations with helium. Ligand evaporation caused by encapsulation of the noble gas atom , 1992 .

[382]  V. Kellö,et al.  Interaction potentials in rare gas-halide ion systems , 1991 .

[383]  P. Hamilton,et al.  Ab initio studies of open‐shell complexes of CO+ with rare gases , 1993 .

[384]  N. Sathyamurthy,et al.  (He,H2+) dynamics revisited , 1993 .

[385]  G. Diercksen,et al.  Symmetry‐adapted perturbation theory potential for the HeK+ molecular ion and transport coefficients of potassium ions in helium , 1994 .

[386]  Sudarko,et al.  Ab initio vibration and ro-vibrational spectrum of the 1A1 state of He2Si2+. , 2002, Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy.

[387]  F. H. Field,et al.  Project SQUID, A Mass Spectrometric Study of Homonuclear and Heteronuclear Rare Gas Molecule Ions. , 1963 .

[388]  M. Crofton,et al.  Infrared spectra of 4HeH+, 4HeD+, 3HeH+, and 3HeD+ , 1989 .

[389]  C. Lin,et al.  CALCULATIONS OF SOME WEAKLY BOUND DIATOMIC MOLECULAR NEGATIVE IONS , 1999 .

[390]  Martin Saunders,et al.  Incorporation of helium, neon, argon, krypton, and xenon into fullerenes using high pressure , 1994 .

[391]  A. Larson,et al.  DISSOCIATIVE RECOMBINATION OF HEH+ : PRODUCT DISTRIBUTIONS AND ION-PAIR FORMATION , 1999 .

[392]  W. Wolff,et al.  Low-velocity ionization in asymmetric systems: a comparative study of the He+-Ne and Ne+-He cases , 1999 .

[393]  Helmut Schwarz,et al.  Formation of endohedral carbon-cluster noble-gas compounds with high-energy bimolecular reactions : C60Hen+ (n=1, 2) , 1991 .

[394]  F. Paesani,et al.  The structure of a weakly bound ionic trimer: Calculations for the 4He2H− complex , 2001 .

[395]  Edmond P. F. Lee,et al.  Interatomic potentials for the Na+—Rg complexes (Rg = He, Ne and Ar) , 1999 .

[396]  K. Hiraoka,et al.  Stability of rare gas cluster ions , 1990 .

[397]  W. Breckenridge,et al.  Bonding in ground-state and excited-state A+.Rg van der Waals ions (A = atom, Rg = rare-gas atom): a model-potential analysis. , 2002, Chemical reviews.

[398]  R. D. Poshusta,et al.  Stability of HeH3 , 1973 .

[399]  J. Callahan,et al.  Molecular Dynamics Simulations and Experimental Studies of the Formation of Endohedral Complexes of Buckminsterfullerene , 1992 .

[400]  S. Nizkorodov,et al.  The infrared spectrum of the N2H+–He ion‐neutral complex , 1995 .

[401]  J. Whitten,et al.  Geometry and dissociation energy of He3 , 1972 .

[402]  A. Metropoulos,et al.  Electric dipole transition moments between the 2Σ+u and 2Σ+g states of the He+2 ion , 1992 .

[403]  D. R. Bates,et al.  Exact wave functions of HeH2+ , 1956, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[404]  J. Dorantes-Dávila,et al.  A possible route to macroscopic formation of endohedral fullerenes , 1995 .

[405]  P. Pyykkö.  Ab Initio Predictions for New Chemical Species , 1990 .

[406]  Martin F. Jarrold,et al.  Structural Information from Ion Mobility Measurements: Effects of the Long-Range Potential , 1996 .

[407]  J. Berkowitz,et al.  Diatomic ions of noble gas fluorides , 1970 .

[408]  P. Siska,et al.  The interaction between He and H+ 2: anisotropy, bond length dependence and hydrogen bonding , 1999 .

[409]  B. Tabbert,et al.  Optical Investigation of Impurities in Superfluid 4He , 1997 .

[410]  F. McLafferty,et al.  Collisional activation and metastable ion characteristics. 59. Efficiency of collisional activation of gaseous organic ions , 1978 .

[411]  Bound and Quasibound States of He2H+ and He2D+ † , 2003 .

[412]  E. A. Mason,et al.  Interaction universality and scaling laws for interaction potentials between closed-shell atoms and ions , 1990 .

[413]  S. Peyerimhoff,et al.  MRD-CI-study of the positive molecular ions ArHe and ArHe2 , 1986 .

[414]  V. Magnasco.  On the α and β parameters in Hückel theory including overlap for simple σ molecular systems , 2002 .

[415]  R. Heller.  Theory of Some van der Waals Molecules , 1941 .

[416]  Martin Saunders,et al.  Stable Compounds of Helium and Neon: He@C60 and Ne@C60 , 1993, Science.

[417]  R. Cooks,et al.  COLLISION-INDUCED DISSOCIATION MASS SPECTROMETRY: TARGET GAS EFFECTS UPON SCATTERING AND CHARGE EXCHANGE , 1981 .

[418]  K. Balasubramanian,et al.  CAS SCF/CI calculations of potential energy surfaces of He3+ and He2+ , 1987 .