title: The d(0), d(1) and d(2) Configurations in Known and Unknown Tetrathiometal Compounds MS(4)(n)()(-) (M = Mo, Tc, Ru; W, Re, Os). A Quantum Chemical Study.
abstract: The known tetrathiometalates MoS(4)(2)(-)(/3)(-), WS(4)(2)(-)(/3)(-), ReS(4)(-)(/2)(-)(/3)(-), and the unknown species TcS(4)(-)(/2)(-), RuS(4)(0/)(-), and OsS(4)(0/)(-)(/2)(-) were calculated using ab initio and DFT methods. The one-electron reduced species with d(1) configuration were shown to exhibit a slight Jahn-Teller distortion (T(d)() --> D(2)(d)()); the largest corresponding stabilization energy was obtained for MoS(4)(3)(-) with -4.17 kcal/mol. Trends in vacuum bonding energies involve a destabilization on going from 5d(n)() to 4d(n)() systems and on reduction from d(0) to d(1) species, with the exception of Ru and Os complexes where the d(1) configurations are more stable than the d(0) forms. The d(2) species ReS(4)(3)(-) and OsS(4)(2)(-) have vacuum bonding energies similar to those of d(1) analogues. The metal contribution to the lowest unoccupied MO (e) of d(0) forms is lowest for the neutral RuS(4) and OsS(4) and highest for the dianions MoS(4)(2)(-) and WS(4)(2)(-). The DFT approach supported by correlated ab initio calculations describes the main features of the electronic spectra of the d(0) complexes. For the experimentally best accessible ReS(4)(n)()(-) system the absorption energies and stretching frequencies were well reproduced, and the related but hitherto unknown OsS(4)(-) ion is predicted to be a fairly stable paramagnetic species.
authors.affiliation: J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejskova 3, CZ-18223 Prague, Czech Republic, Institut für Theoretische Chemie der Universität, Pfaffenwaldring 55, D-70550 Stuttgart, Germany, Afdeling Theoretische Chemie, Vrije Universiteit, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands, and Institut für Anorganische Chemie der Universität, Pfaffenwaldring 55, D-70550 Stuttgart, Germany.
authors.forename: Stanislav
authors.initials: S
authors.lastname: Zális
authors.forename: Hermann
authors.initials: H
authors.lastname: Stoll
authors.forename: Evert Jan
authors.initials: EJ
authors.lastname: Baerends
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Kaim