Organometallics of diphosphazanes. Part 10. Dinuclear group 6 metal carbonyl complexes bridged by a cyclodiphosphazane in its cis or trans form
摘要:
Mononuclear Group 6 metal tetracarbonyl complexes containing a cyclodiphosphazane ligand, [PhNP(OC(6)H(4)Me-p)](2) (L), have been used as synthons to prepare homo- and hetero-bimetallic complexes in which the cyclodiphosphazane bridges the two metal centres in its cis or trans isomeric forms. The dimolybdenum complex [Mo-2(eta(5)-C5H5)(2)(CO)(4)(mu-L)] has also been synthesized. The trends in P-31 NMR chemical shifts and the structural features as revealed by X-ray crystallography are discussed.
The reactions of cyclodiphosphazanes [PhNP(OR)]2 (R = CH2CF3 (1) and C6H4Me-p (2)) with Group 6 metal carbonyl derivatives have been investigated. The stereochemistry of the ligand appears to play a significant role in determining its coordination behaviour. The cyclodiphosphazane 1 (isolated as the trans-isomer) affords the dinuclear complexes 9-11 in which the two metal centres are bridged by the diphosphazane ligand. In contrast the cyclodiphosphazane 2 (isolated as a 3/1 mixture of cis- and trans-isomers) yields the mononuclear complexes 3-7 in which the cyclodiphosphazane is coordinated in the eta1-fashion. The structures of [W(CO4(NHC5H10){(PhNP(OC6H4Me-p))2}] (6) and [{Mo(CO)4(NHC5H10)}2{mu-[PhNP(OCH2CF3)]2}] (9a) have been determined by X-ray crystallography.
Di- and tri-metallic complexes containing two bridging cyclodiphosphazane ligands: the crystal structure of [MO<sub>2</sub>(CO)<sub>8</sub>{µ-cis-[PhNP(OC<sub>6</sub>H<sub>4</sub>Me-p)]<sub>2</sub>}<sub>2</sub>]
作者:Venkata S. Reddy、Setharampattu S. Krishnamurthy、Munirathinam Nethaji
DOI:10.1039/dt9950001933
日期:——
The reactions of the mononuclear cyclodiphosphazane complexes, cis-[Mo(CO)(4)cis-[PhNP(OR)](2)}(2)] with [Mo(CO)(4)(nbd)] (nbd = norbornadiene). [Mo(CO)(4)(NHC5H10)(2)] or [MCl(2)(cod)] (cod = cycloocta-1,5-diene) afforded the homobimetallic complexes; [Mo-2(CO)(8)mu-cis-[PhNP(OR)](2)}(2)] (R = C(5)H(4)Me-p 5 or CH2CF3 6) or the heterobimetallic complexes. [Mo-2(CO)(8)mu-cis-[PhNP(OE)](2)}(2)MCl(2)] (R = C(6)H(4)Me-p; M = Pd 7 or Pt 8). In all the above complexes, the two metal moieties are bridged by two cyclodiphosphazane ligands. The reactions of the mononuclear complexes, cis-[M(CO)(4)(A)cis-[PhNP(OC(6)H(4)Me-p)](2)}] with (M'Cl-2(cod)] afforded the trinuclear complexes, cis-[M'Cl-2[M(CO)(4)(A)cis-[PhNP(OC(6)H(4)Me-p)](2)}](2)] (M' = Pd, M = Mo, A = P(OMe)(3) 10; M' = Pt, M = Mo. A = P(OMe)(3) 11; M' = Pd. M = W. A = NHC5H10 12; M' = Pt, M = W. A = NHC5H10 13). The structure of the complex 5 has been determined by single-crystal X-ray crystallography.
Krishnamurthy, S. S.; Reddy, V. Sreenivasa; Chandrasekaran, A., Phosphorus, Sulfur and Silicon and the Related Elements, 1992, vol. 64, # 1-4, p. 99 - 106
作者:Krishnamurthy, S. S.、Reddy, V. Sreenivasa、Chandrasekaran, A.、Nethaji, M.