Selenoxopropadienylidene (CCCSe) as a Bridging Ligand

Abstract

The reaction of [W(CCCSiMe 3 )(CO) 2 (Tp*)] (Tp* = hydrotris-(3,5-dimethylpyrazol-1-yl)borate) with [ n Bu 4 N]F and selenium in the presence of [RuCl(PPh 3 ) 2 (η-C 5 H 5 )] affords a mixture of the tricarbido complex [WRu(μ-CCC)(CO) 2 (PPh 3 ) 2 (η-C 5 H 5 )(Tp*)] and the selenoxopropadienylidene (C 3 Se) complex [WRu(μ-CCCSe)(CO) 2 (PPh 3 ) 2 (η-C 5 H 5 )(Tp*)], both of which were structurally characterized. The formation of the bimetallic C 3 Se complex is consistent with the intermediacy of the salt [ n Bu 4 N] [W(CCCSe)(CO) 2 (Tp*)], which could be observed spectroscopically and computationally interrogated, but not yet isolated. Article pubs.acs.org/Organometallics

Dihydrobis(methimazolyl)borato complexes of ruthenium and osmium

“…The complex 3c was also structurally characterised (Figure 4). Data for simple non-chelated selenolates of ruthenium that adhere to the 18-electron rule comprise the alkynylselenolates [Ru(SeCºCR)(PPh3)2(h-C5H5)] (R = Ph, SiMe3, 36 CºW(CO)2Tp* 37 , Tp* = hydrotris(dimethylpyrazolyl)borate and the selenobenzoate [Ru{SeCOC6H3(NO2)2-3,5}(CO)2(h-C5H4 t Bu)] 38 with Ru-Se bond lengths in the range 2.50 -2.55 Å and angles at selenium of 102 -106°. The trigonal bipyramidal and coordinatively unsaturated complex [Ru(SeC6HMe4)4(NCMe)] 39 shows a significant lengthening of the equatorial Ru-Se bond lengths (2.316 -2.330 Å) relative to the unique axial selenolate (2.496Å) although this is not manifest in a significant opening up of the Ru-Se-C angles (108.2 -109.…”

Pentadiynylidyne and Pentacarbido Complexes

“…Treating 2 with [RuCl(PPh 3 ) 2 (η‐C 5 H 5 )] in the presence of KF in methanol/THF (1:1) allowed the isolation of the bimetallic pentacarbido complex [(Tp*)(CO) 2 W(μ‐CC≡CC≡C)Ru(PPh 3 ) 2 (Cp)] ( 5 ) in 74 % yield (Scheme , Figure ). This reagent was chosen because the corresponding tricarbido complex [(Tp*)(CO) 2 W(μ‐CC≡C)Ru(PPh 3 ) 2 (Cp)] ( 6 ) is known and because the only previously reported bimetallic pentacarbido complex other than the cumulenic ReC 5 Mn complex discussed above is [(Tp*)(CO) 2 Mo(μ‐CC≡CC≡C)Ru(dppe)(Cp*)] ( 7 , Cp*=η‐C 5 Me 5 ), which arose from the Pd 0 /Cu I mediated reaction of [Mo(≡CBr)(CO) 2 (Tp*)] with [Ru(C≡CC≡CAuPPh 3 )(dppe)(Cp*)] …”

Synthesis and reactivity of selenium functionalised allylidynes and propargylidynes

“…An indication of their viability was however provided by the isolation of a bimetallic complex [WRu(µ-C3Se)(CO)2(PPh3)2(Tp*)(h-C5H5)] which arose from the reaction of 1 with moist [ n Bu4N]F ('TBAF') ‡ in the presence of elemental (grey) selenium to afford the putative salt [ n Bu4N][W(CCCSe)(CO)2(Tp*)] which, although not isolable, could be trapped by reaction with [RuCl(PPh3)2(h-C5H5)] (Scheme 2). 5 Scheme 2. Synthesis of a µ-C3Se Bimetallic Complex.…”

“…Synthesis of a µ-C3Se Bimetallic Complex. 5 (a) [ n Bu4N]F; (b) 1 /nSen; (c) [RuCl(PPh3)2(h-C5H5)]. 5 We therefore commenced our studies by computationally interrogating the, as yet hypothetical, complex [W(≡CC≡CSeMe)(CO)2{HB(pz)3}] as a computationally simpler analogue of the target complex [W(≡CC≡CSePh)(CO)2(Tp*)] (2).…”

“…5 (a) [ n Bu4N]F; (b) 1 /nSen; (c) [RuCl(PPh3)2(h-C5H5)]. 5 We therefore commenced our studies by computationally interrogating the, as yet hypothetical, complex [W(≡CC≡CSeMe)(CO)2{HB(pz)3}] as a computationally simpler analogue of the target complex [W(≡CC≡CSePh)(CO)2(Tp*)] (2). Figure 1 depicts optimised geometry for this complex, and includes the HOMO-1 orbital which of is interest in that it comprises WC and CC p-bonding contributions in addition to selenium lone pair character.…”