Reactions of Tungsten Alkylidynes with Thionyl Chloride

Abstract

The reaction of [W(⋮CR)(CO)2(η-C5H5)] (R = C6H3Me2-2,6) with thionyl chloride provides the metallacyclic alkylidene complex [W(CRSCRS)Cl3(η-C5H5)], while similar treatment of [W(⋮CR)(CO)2{HB(pz)3}] (pz = pyrazol-1-yl) provides the alkylidyne complex [W(⋮CR)Cl2{HB(pz)3}], which is also obtained from the reaction of [W(⋮CR)(CO)2{HB(pz)3}] with [Fe(η-C5H5)2]Cl. The crystal structures of [W(⋮CC6H2Me3-2,4,6)(CO)2{HB(pz)3}], [W(CRSCRS)Cl3(η-C5H5)], and [W(⋮CR)Cl2{HB(pz)3}](R = C6H3Me2-2,6) are reported.

Regioselective Dimetallapolycarbyl Hydrometalation

“…Crystallographic grade crystals of 3a were obtained, and the results of a structure determination are summarized in Figure . This confirms (a) the pseudo-octahedral geometries at ruthenium and tungsten, notwithstanding the geometric constraints of HB(pz) 3 chelation (N−W−N angles 79.83−81.83°), (b) the internally referenced trans influences of the alkylidyne ligands on tungsten relative to the carbonyl ligands (29 and 35σ for W1 and W2, respectively), and (c) the connectivity and hydrometalation regioselectivity of the WC 6 W spine. Thus, the bond lengths W1⋮C101, C101−C102, C102⋮C103, C103−104, C104C105, C105−C106, and C106⋮W2 (Figure ) fall respectively within norms for W⋮C, C−C, C⋮C, C−C, CC, C−C, and C⋮W bonds.…”

Reactions of (Silyl)(silylene)tungsten and -molybdenum Complexes with Sulfur Reagents

“…Crystal structure analysis of 3 (Figure ) revealed the three-legged piano-stool geometry at the metal, two of which constitute a metallacyclohexene fragment. The WC(32) bond distance (1.935(4) Å) is at the shorter limit for those of typical WC double bonds in the metallacyclic compounds (1.94−2.14 Å) and within the range of the usual WC−SiMe 3 double bonds (1.87−1.96 Å) . The sum of the three bond angles around C(32) is 360(1)°, which implies the sp 2 hybridization of C(32).…”

Borylcarbyne Complexes: [Mo(≡CBR2)(CO)2{HB(pzMe2)3}] (BR2= B(NMe2)2, BO2C6H4; pz = pyrazol-1-yl)

“…The orientation that is adopted by the “BO 2 C 6 H 4 ” heterocycle would, however, appear to be that which aligns the carbyne acceptor orbitals with the coordination axes defined by the pseudo-octahedral MoN 3 C 3 donor set. This is also observed for [Mo(CNEt 2 )(CO) 2 {HB(pzMe 2 ) 3 }] but is in contrast with the geometries of [Mo(CDMAP)(CO) 2 {HB(pzMe 2 ) 3 }] + and the aryl derivatives [M(CC 6 H 3 Me 3 -2,4,6)(CO) 2 {HB(pzMe 2 ) 3 }] (M = Mo, W) and [W(CC 6 H 4 Me-4)(CO) 2 {HB(pzMe 2 ) 3 }] (Figure ), , where the carbyne substituents lie in a plane straddled by the two carbonyl ligands to minimize interligand steric interactions.…”