Molecular structure and bonding in octamethylporphyrin tin(II), SnN4C28H28

作者：Girichev Georgiy V^*; Giricheva Nina I; Koifman Oscar I; Minenkov Yury V; Pogonin Alexander E; Semeikin Alexander S; Shlykov Sergey A

来源：Dalton Transactions, 2012, 41(25): 7550-7558.

DOI：10.1039/c2dt12499h

Gas-phase electron diffraction was applied for the molecular structure determination of octamethylporphyrin tin(II), SnN4C28H28, at the temperature of 706(10) K. The molecule was found to possess C-4v symmetry with the Sn atom 1.025(30) angstrom above the plane of the N atoms and the following main internuclear distances (r(h1), angstrom): Sn-N = 2.301(9), C-alpha-N = 1.360(8), C-alpha-C-beta = 1.453(4), C-alpha-C-m = 1.395(4), C-beta-C-CH3 = 1.498(4). Quantum chemical calculations, DFT (B3LYP, BP86, PBE, PBE0) with cc-pVDZ, cc-pVTZ and cc-pVQZ basis sets reproduce the experimental bond distances with accuracy within 0.03 angstrom. According to NBO(B3LYP/cc-pVTZ) analysis, the direct donation gives a prevailing contribution to Sn-N bonding, decreasing the net charge on Sn from formal +2 to +1.28. The substitution effects at the pyrrole rings are discussed. The ability of different theoretical methods to predict the structure of this compound is analyzed.

• 出版日期2012