Reactions of benzothiazolide triosmium clusters with tetramethylthiourea

Experimental and computational preference for phosphine regioselectivity and stereoselective tripodal rotation in HOs3(CO)8(PPh3)2(μ-1,2-N,C-η1,κ1-C7H4NS)

“…In this scenario, the P--Os atoms display an obtuse angle, a feature underscored by numerous structural studies involving related trimetallic clusters where the P--Os bond angle ranges from 105-117 . 14,[16][17][18]24 The computed P--Os bond angle in D1 is 109 . Assuming a xed cluster polyhedron, expansion of the P--Os bond angle in D1 effectively permutes the PPh 3 ligand to the other equatorial site at the nitrogen-substituted osmium center.…”

“…5 c , e ,16 To our knowledge, only one reactivity report exists for the 1,2-N,C isomer to date and this involves the cyclometalation of thiourea at cluster 1. 17 Herein we present our data on the regiochemical preference for PPh 3 substitution in cluster 1, along with the results of electronic structure calculations that help place the observed outcome in each substitution step in context with the NMR properties and the solid-state structures determined for 2 and 3.…”

Dppm-substituted ruthenium clusters with capping sulfido and selenido ligands derived from thiourea, tetramethylthiourea and elemental selenium

“…In contrast, tetramethylthiourea reacts with [Os 3 (CO) 12 ] in the presence of Me 3 NO AE 2H 2 O giving [Os 3 (CO) 11 {g 1 -SC(NMe 2 ) 2 }], [Os 3 (l-OH)(lMeOCO){g 1 -SC(NMe 2 ) 2 }(CO) 9 ] and [Os 3 (l-H)(l 3 -S)(lMeOCO){g 1 -SC(NMe 2 ) 2 }(CO) 8 ] containing S-coordinated tetramethylthiourea ligands [12]. We recently began systematic investigations of tetramethylthiourea reactivity with unsaturated triosmium clusters for which a variety of ligand coordination modes and transformations have been demonstrated including g 1 -S-coordination, the latter being useful for further transformation [13]. Most recently we have investigated the reaction of tetramethylthiourea with the dppm-bridging triosmium cluster [Os 3 (CO) 10 -(l-dppm)] (1) and obtained only [Os 3 (l 3 -S) 2 (CO) 7 (ldppm)] as two separable isomers [14] (Scheme 3).…”