TY - JOUR

T1 - Ambidentate coordination in hydrogen bonded dimethyl sulfoxide, (CH 3)2SO⋯H3O+, and in dichlorobis(dimethyl sulfoxide) palladium(ii) and platinum(ii) solid solvates, by vibrational and sulfur K-edge X-ray absorption spectroscopy

AU - Risberg, Emiliana Damian

AU - Mink, János

AU - Abbasi, Alireza

AU - Skripkin, Mikhail Yu

AU - Hajba, Laszló

AU - Lindqvist-Reis, Patric

AU - Bencze, Éva

AU - Sandström, Magnus

PY - 2009/1/1

Y1 - 2009/1/1

N2 - The strongly hydrogen bonded species (CH3)2SO⋯ H3O+ formed in concentrated hydrochloric acid displays a new low energy feature in its sulfur K-edge X-ray absorption near edge structure (XANES) spectrum. Density Functional Theory-Transition Potential (DFT-TP) calculations reveal that the strong hydrogen bonding decreases the energy of the transition S(1s) → LUMO, which has antibonding σ*(S-O) character, with about 0.8 eV. Normal coordinate force field analyses of the vibrational spectra show that the SO stretching force constant decreases from 4.72 N cm-1 in neat liquid dimethyl sulfoxide to 3.73 N cm -1 for the hydrogen bonded (CH3)2SO⋯ H3O+ species. The effects of sulfur coordination on the ambidentate dimethyl sulfoxide molecule were investigated for the trans-Pd((CH3)2SO)2Cl2, trans-Pd((CD3)2SO)2Cl2 and cis-Pt((CH3)2SO)2Cl2 complexes with square planar coordination of the chlorine and sulfur atoms. The XANES spectra again showed shifts toward low energy for the transition S(1 s) → LUMO, now with antibonding σ*(M-Cl, M-S) character, with a larger shift for M = Pt than Pd. DFT-TP calculations indicated that the differences between the XANES spectra of the geometrical cis and trans isomers of the M((CH 3)2SO)2Cl2 complexes are expected to be too small to allow experimental distinction. The vibrational spectra of the palladium(II) and platinum(II) complexes were recorded and complete assignments of the fundamentals were achieved. Even though the M-S bond distances are quite similar the high covalency especially of the Pt-S bonds induces significant increases in the S-O stretching force constants, 6.79 and 7.18 N cm -1, respectively.

AB - The strongly hydrogen bonded species (CH3)2SO⋯ H3O+ formed in concentrated hydrochloric acid displays a new low energy feature in its sulfur K-edge X-ray absorption near edge structure (XANES) spectrum. Density Functional Theory-Transition Potential (DFT-TP) calculations reveal that the strong hydrogen bonding decreases the energy of the transition S(1s) → LUMO, which has antibonding σ*(S-O) character, with about 0.8 eV. Normal coordinate force field analyses of the vibrational spectra show that the SO stretching force constant decreases from 4.72 N cm-1 in neat liquid dimethyl sulfoxide to 3.73 N cm -1 for the hydrogen bonded (CH3)2SO⋯ H3O+ species. The effects of sulfur coordination on the ambidentate dimethyl sulfoxide molecule were investigated for the trans-Pd((CH3)2SO)2Cl2, trans-Pd((CD3)2SO)2Cl2 and cis-Pt((CH3)2SO)2Cl2 complexes with square planar coordination of the chlorine and sulfur atoms. The XANES spectra again showed shifts toward low energy for the transition S(1 s) → LUMO, now with antibonding σ*(M-Cl, M-S) character, with a larger shift for M = Pt than Pd. DFT-TP calculations indicated that the differences between the XANES spectra of the geometrical cis and trans isomers of the M((CH 3)2SO)2Cl2 complexes are expected to be too small to allow experimental distinction. The vibrational spectra of the palladium(II) and platinum(II) complexes were recorded and complete assignments of the fundamentals were achieved. Even though the M-S bond distances are quite similar the high covalency especially of the Pt-S bonds induces significant increases in the S-O stretching force constants, 6.79 and 7.18 N cm -1, respectively.

UR - http://www.scopus.com/inward/record.url?scp=59949094669&partnerID=8YFLogxK

U2 - 10.1039/b814252a

DO - 10.1039/b814252a

M3 - Article

C2 - 19462654

AN - SCOPUS:59949094669

SP - 1328

EP - 1338

JO - Dalton Transactions

JF - Dalton Transactions

SN - 1477-9226

IS - 8

ER -