Geminally Substituted Tris(acenaphthyl) and Bis(acenaphthyl) Arsines, Stibines, and Bismuthine: A Structural and Nuclear Magnetic Resonance Investigation.

Tris(acenaphthyl)- and bis(acenaphthyl)-substituted pnictogens (iPr2P-Ace)3E (2-4) (E = As, Sb, or Bi; Ace = acenaphthene-5,6-diyl) and (iPr2P-Ace)2EPh (5 and 6) (E = As or Sb) were synthesized and fully characterized by multinuclear nuclear magnetic resonance (NMR), high-resolution mass spectrometry, elemental analysis, and single-crystal X-ray diffraction. The molecules adopt propeller-like geometries with the restricted rotational freedom of the sterically encumbered iPr2P-Ace groups resulting in distinct NMR features. In the tris(acenaphthyl) species (2-4), the phosphorus atoms are isochronous in the (31)P{(1)H} NMR spectra, and the rotation of the three acenaphthyl moieties around the E-Cipso bond is locked. On the other hand, the bis(acenaphthyl) species show a fluxional behavior, resulting in an AX to A2 spin system transition in the (31)P{(1)H} variable-temperature NMR spectra. This allowed elucidation of remarkable through-space couplings ((8TS)JPP) of 11.5 Hz (for 5) and 25.8 Hz (for 6) at low temperatures. In addition, detailed line shape analysis of the thermodynamic parameters of the restricted rotation of the "propeller blades" in 5 was performed in the intermediate temperature region and also at coalescence. The lone pairs on the pnictogen atoms in 2-6 are oriented such that they form a bowl-shaped area that is somehow buried within the molecule.

[1]  A. Slawin,et al.  Structural, spectroscopic and computational examination of the dative interaction in constrained phosphine-stibines and phosphine-stiboranes. , 2015, Chemistry.

[2]  A. Slawin,et al.  Conformational dependence of through-space tellurium-tellurium spin-spin coupling in peri-substituted bis(tellurides). , 2015, Chemistry.

[3]  A. Slawin,et al.  Peri-substituted phosphorus-tellurium systems-an experimental and theoretical investigation of the P···Te through-space interaction. , 2015, Inorganic chemistry.

[4]  Jean‐Cyrille Hierso.  Indirect nonbonded nuclear spin-spin coupling: a guide for the recognition and understanding of "through-space" NMR J constants in small organic, organometallic, and coordination compounds. , 2014, Chemical reviews.

[5]  Kevin R. D. Johnson,et al.  Secondary diphosphine and diphosphido ligands: synthesis, characterisation and group 1 coordination compounds. , 2014, Dalton transactions.

[6]  A. Slawin,et al.  Synthetic, structural, NMR, and computational study of a geminally bis(peri-substituted) tridentate phosphine and its chalcogenides and transition-metal complexes. , 2013, Inorganic chemistry.

[7]  F. Tuczek,et al.  Molybdenum(0) dinitrogen complexes with polydentate phosphine ligands for synthetic nitrogen fixation: Geometric and electronic structure contributions to reactivity , 2013 .

[8]  A. Ellern,et al.  Unusual structural motif in a zwitterionic Fe(II) complex of a tetradentate phosphine. , 2012, Dalton transactions.

[9]  A. Slawin,et al.  Intramolecular phosphine-phosphine donor-acceptor complexes. , 2009, Inorganic chemistry.

[10]  A. Slawin,et al.  1,8,9-Substituted anthracenes, intramolecular phosphine donor stabilized metaphosphonate and phosphenium. , 2007, Dalton transactions.

[11]  M. Yamashita,et al.  Synthesis of a New Tridentate Anthracene Ligand Bearing (i-Pr)2P Group at 1,8-Positions: Facile Bond Switch on Tetracoordinate Boron Atom , 2001 .

[12]  S. Batsanov,et al.  Van der Waals Radii of Elements , 2001 .

[13]  C. Kubiak,et al.  Synthesis of the Tetradentate Phosphine α,α,α‘,α‘-Tetrakis(diphenylphosphino)-p-xylene (dppx) and Crystal and Molecular Structure of (CO)3Fe(dppx)Fe(CO)3 , 1997 .

[14]  A. W. Cordes,et al.  Chemistry of organometalloid complexes with potential antidotes: structure of an organoarsenic(III) dithiolate ring , 1990 .

[15]  L. Curtiss,et al.  Intermolecular interactions from a natural bond orbital, donor-acceptor viewpoint , 1988 .

[16]  C. W. Hudson,et al.  POLYPHOSPHINO MACROCYCLIC LIGAND SYSTEMS , 1977 .

[17]  Kenneth B. Wiberg,et al.  Application of the pople-santry-segal CNDO method to the cyclopropylcarbinyl and cyclobutyl cation and to bicyclobutane , 1968 .

[18]  L. Venanzi,et al.  746. The preparation and complex-forming properties of one tritertiary and one tetratertiary phosphine , 1963 .

[19]  H. R. Watson,et al.  283. The preparation of di- and tri-tertiary phosphines , 1962 .