Spectroscopy and dynamics of methylamine. II. Rotational and vibrational structures of CH3NH2 and CH3ND2 in cationic D0 states

Accurate and precise ionization energies of methylamines (CH3NH2 and CH3ND2) are determined to be 9.0422±0.0012 and 9.0532±0.0012 eV, respectively, by (1+1′) two-photon mass-analyzed threshold ionization (MATI) spectroscopy. From selective ionizations from specified intermediate quantum states, fundamental frequencies of amino-wagging and CH3-rocking modes of CH3NH2+ (CH3ND2+) in D0 states are determined to be 738 (573) and 1013 (1024) cm−1, respectively. The frequency of the amino wag is largely blueshifted from that of the neutral S1 state, while the CH3-rocking frequency is little shifted from that of S1. Internal rotational constants associated with the nearly free internal rotation of the top (amino group) with respect to the frame (methyl group) about the C–N axis are accurately determined, from which the geometries of methylamine ions are revealed. Barrier heights for torsional motion in CH3ND2+ are determined to be 25±5 and 34±5 cm−1 at the origin and first ND2-wagging bands, respectively. Mode-re...

[1]  Young S. Choi,et al.  Vibrational structures of predissociating methylamines (CH3NH2 and CH3ND2) in à states: Free internal rotation of CH3 with respect to NH2 , 2002 .

[2]  Young S. Choi,et al.  Resonant-enhanced two photon ionization and mass-analyzed threshold ionization spectroscopy of jet-cooled 2-aminopyridines (2AP–NH2,–NHD,–NDH,–ND2) , 2002 .

[3]  R. Damrauer,et al.  Computational studies of aliphatic amine basicity. , 2002, The Journal of organic chemistry.

[4]  N. Mason,et al.  Electronic excitation and optical cross sections of methylamine and ethylamine in the UV–VUV spectral region , 2002 .

[5]  A. Bach,et al.  Vibronic structure and photodissociation dynamics of the à state of jet-cooled ammonia , 2002 .

[6]  Min-Gyu Lee,et al.  Biosorption Characteristics in the Mixed Heavy Metal Solution by Biosorbents of Marine Brown Algae , 2002 .

[7]  Sang Kyu Kim,et al.  Observation of conformation-specific pathways in the photodissociation of 1-iodopropane ions , 2002, Nature.

[8]  Dennis J. Clouthier,et al.  AsyrotWin: A 32-bit Windows version of Asyrot, A program for the analysis of high resolution singlet-singlet band spectra of asymmetric tops , 2001 .

[9]  Sang Kyu Kim,et al.  One-photon mass-analyzed threshold ionization spectroscopy of 1- and 2-iodopropanes in vacuum ultraviolet , 2001 .

[10]  T. Sears,et al.  Vibrational effects on the torsional motion of ethyl radical , 1999 .

[11]  J. Beebe-Wang,et al.  INFRARED SPECTRUM OF THE CH2 OUT-OF-PLANE FUNDAMENTAL OF C2H5 , 1999 .

[12]  K. Kimura.  Development of laser photoelectron spectroscopy based on resonantly enhanced multiphoton ionization , 1999 .

[13]  M. Ashfold,et al.  State to state recoil anisotropies in the photodissociation of deuterated ammonia , 1998 .

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

[15]  M. Ashfold,et al.  Near ultraviolet photolysis of ammonia and methylamine studied by H Rydberg atom photofragment translational spectroscopy , 1997, Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences.

[16]  C. Dion,et al.  On the electronic states and photochemistry of simple alkyl amines , 1997 .

[17]  K. Morokuma,et al.  AB INITIO STUDY OF THE PHOTOCHEMICAL DISSOCIATION OF METHYLAMINE , 1996 .

[18]  J. Hepburn.  Photoelectron spectroscopy in a new light: zero kinetic energy (ZEKE) photoelectron spectrosocopy with coherent vacuum ultraviolet light , 1996 .

[19]  M. Ashfold,et al.  Near-UV photolysis of methylamine studied by H-atom photofragment translational spectroscopy , 1996 .

[20]  E. Bernstein,et al.  On the low lying excited states of methyl amine , 1995 .

[21]  L. Butler,et al.  Competing Bond Fission and Molecular Elimination Channels in the Photodissociation of CH3NH2 at 222 nm , 1995 .

[22]  K. Lehmann,et al.  MICROWAVE DETECTED, MICROWAVE-OPTICAL DOUBLE RESONANCE OF NH3, NH2D, NHD2,AND ND3. II: PREDISSOCIATION DYNAMICS OF THE A STATE , 1994, chem-ph/9412001.

[23]  I. Fischer,et al.  State-to-state photoionisation dynamics probed by zero kinetic energy (ZEKE) photoelectron spectroscopy , 1994 .

[24]  E. Davidson,et al.  Zero kinetic energy photoelectron spectra of jet‐cooled aniline , 1993 .

[25]  H. Krause,et al.  Dissociation of state-selected complex ions studied by mass-selective pulsed field threshold ionization spectroscopy , 1992 .

[26]  J. Knee,et al.  High resolution threshold photoelectron spectroscopy of aniline and aniline van der Waals complexes , 1992 .

[27]  M. Takahashi,et al.  Vibrational spectra of aniline–Arn van der Waals cations (n=1 and 2) observed by two‐color ‘‘threshold photoelectron’’ [zero kinetic energy (ZEKE)‐photoelectron] spectroscopy , 1992 .

[28]  Philip J. M. Johnson,et al.  Mass analyzed threshold ionization spectroscopy , 1991 .

[29]  K. Fuke,et al.  Photodissociation dynamics of NH3, NH2D, NHD2, and ND3 : rovibronic absorption analysis of the Ã-X transition , 1991 .

[30]  E. W. Schlag,et al.  High-Resolution Zero Kinetic Energy (ZEKE) Photoelectron Spectroscopy of Molecular Systems , 1991 .

[31]  J. Hougen,et al.  A group-theoretical formalism for the large-amplitude vibration-rotation problem in methylamine-d1 , 1990 .

[32]  M. Krȩglewski.  The geometry and inversion-internal rotation potential function of methylamine , 1989 .

[33]  W. J. Lafferty,et al.  Far-infrared spectrum of methyl amine: Assignment and analysis of the first torsional state , 1988 .

[34]  T. Xiang,et al.  Infrared laser dissociation of CH3NH2 in a molecular beam: Initial translational and internal energy distributions, and relaxation of NH2 , 1986 .

[35]  L. Ziegler.  Rovibronic absorption analysis of the à ← X̃ transition of ammonia , 1985 .

[36]  K. Müller-Dethlefs,et al.  Two-colour photoionization resonance spectroscopy of NO: Complete separation of rotational levels of NO+ at the ionization threshold , 1984 .

[37]  F. Stuhl,et al.  Argon fluoride (193 nm) laser photolysis of HN3, methylamine (CH3NH2), and hydrazine (N2H4): formation of excited imidogen (NH) radicals , 1984 .

[38]  M. Tsuboi,et al.  The 240 nm band system of methylamine: a preliminary analysis of the rotational structure of the 0–0 band of CH3ND2 , 1982 .

[39]  M. Robin.  Handbook of He(I) photoelectron spectra of fundamental organic molecules : K. Kimura, S. Katsumata, Y. Achiba, T. Yamazaki and S. Iwata, 1981, Japan Scientific Societies Press, Tokyo, ISBN 4-7622-0263-X and Halsted Press, New York, 268 pp., US $44.95, ISBN 0-470-27200-7. , 1982 .

[40]  P. Bunker,et al.  Molecular symmetry and spectroscopy , 1979 .

[41]  M. Bowers.  Gas phase ion chemistry , 1979 .

[42]  M. Krȩglewski.  Vibration-inversion-internal rotation-rotation Hamiltonian for methylamine , 1978 .

[43]  M. Bowers,et al.  Quantitative proton affinities, ionization potentials, and hydrogen affinities of alkylamines , 1976 .

[44]  M. Bowers,et al.  Analysis of the mechanism of reaction of H3+ [tritium ion] with ethylene oxide and acetaldehyde , 1971 .

[45]  M. Tsuboi,et al.  The structure of the methylamine molecule in an excited electronic state , 1969 .

[46]  J. Michael,et al.  THE PHOTOCHEMISTRY OF METHYLAMINE , 1963 .

[47]  D. Lide,et al.  Structure of the Methylamine Molecule. II. Theory of Internal Motions and Application to CD3ND2 , 1957 .

[48]  R. Lord,et al.  Rotation‐Vibration Spectra of Methyl Amine and Its Deuterium Derivatives , 1957 .

[49]  T. Itoh,et al.  Microwave Investigation of Hindered Rotation and Inversion of Methylamine , 1954 .

[50]  E. Tannenbaum,et al.  The Far Ultraviolet Absorption Spectra of Simple Alkyl Amines , 1953 .