Synthesis and structure of titanium tetrathiolate and tantalum pentathiolate complexes. Metal-sulfur bonding in early transition metal compounds

Syntheses, Structures, and Properties of Trinuclear Copper(I)/Titanium(IV) Thiolate Complexes

“…The oven was programmed to ramp at a rate of 2°C/min to 500°C under a static pressure of N 2 and hold at this temperature for 1 h before cooling to room temperature. The solid residues in the porcelain or quartz boats were characterized by powder X-ray analysis, and the volatile cleavage products deposited in the part of the tube outside the furnace and in the cool trap were collected for 1 H, 13 C, and 31 P NMR spectroscopy.…”

“…1 H, 13 C, and 31 P NMR spectra were recorded with a Bruker Avance II 500. Thermogravimetric analyses were run in Al 2 O 3 crucibles with a thermobalance STA 409 from Netzsch in a dynamic helium gas flow (25 mL/min) and under vacuum conditions 6 ϫ 10 -7 mbar at a heating rate of 2°C/min.…”

“…After cooling, most of the cleavage products outside the oven solidified to result in off-white crystals and a yellow oil. From identification by 1 H, 13 C, and 31 P NMR the main cleavage products are SPh 2 and PPh 3 with traces of SPPh 3 and OPPh 3 (Scheme 3).…”

“…[9,10] However, only a few homoleptic titanium complexes with monodentate thiolato ligands have been characterized by single-crystal X-ray to date. Examples include [Li(OEt 2 ) 3 ][Ti(S-2,4,6-iPr 3 C 6 H 2 ) 4 ], [11] [NMe 2 H 2 ][Ti 2 -(SMe) 9 ], [Ti 3 (SMe) 12 ], [12] [Ti{S-1,3,4,6-C 6 H(CH 3 ) 4 } 4 ], [13] [NEt 4 ] 2 [Ti(SPh) 6 ], [14] [Li(C 4 H 8 O) 4 ][Ti 2 (SPh) 9 ], [15] [NH 2 9 ], [7] and [NH 2 Et 2 ] 2 [Ti(SC 6 F 5 ) 6 ], some of them isolated only in low yields. [8] [ Interest in the combination of an early and a late transition metal in a heterobimetallic complex arises because the combination of two different metal atoms, which are electrondeficient and electron-rich, respectively, offers the possibility of Lewis acid activation of a substrate molecule bound to the electron-rich metal center.…”

μ-Oxo-bis{isopropoxo[2,2′-(methylenedithio)bis(6-tert-butyl-4-methylphenolato)]titanium(IV)}

“…This reflects the hemilabile nature of the Ti-S bond. The Ti-O distances are not equivalent, the distances to the alcoholate and O atoms being shorter than those to the phenolate O atoms (Corwin et al, 1995;Amor et al, 2001). This finding suggests that for phenolate O atoms, -donation from lone pairs of electrons from an O atom is directed toward the phenyl ring, while for alcoholate O atoms it is toward the metal.…”