3-Hexyne Complexes of Molybdenum(II) and Tungsten(II).
Crystal Structures of [WI
2(CO)(PPh
3)
2(
2-EtC
2Et)] and [WI
2(CO){Ph
2P(CH
2)
3PPh
2}(
2-EtC
2Et)]
Mutlaq Al-Jahdali
a, Paul K. Baker
a;, Michael G. B. Drew
b;aDepartment of Chemistry, University of Wales, Bangor, Gwynedd, LL57 2UW, UK
bDepartment of Chemistry, University of Reading, Whiteknights, Reading, RG6 6AD, UK Z. Naturforsch.54 b,171–178 (1999); received August 13, 1998
3-Hexyne Complexes, Molybdenum(II), Tungsten(II)
Treatment of [MI2(CO)3(NCMe)2] (M = Mo, W) with two equivalents of EtC2Et in CH2Cl2at 0C yields the bis(3-hexyne) complexes [MI2(CO)(NCMe)(2-EtC2Et)2] (1and2). Complexes 1and2react with two equivalents of PPh3in CH2Cl2to give the complexes [MI2(CO)(PPh3)2
(2-EtC2Et)] (3 and 4). The molecular structure of 4 (M = W) has been crystallographi- cally determined and has a pseudo-octahedral geometry with the two PPh3 ligands trans to each other with the two cis-iodo-ligands, which together with the carbonyl and 3-hexyne ligand are occupying the equatorial plane. Reaction of 1and 2 with an equimolar amount of Ph2P(CH2)nPPh2 (for M = Mo, n = 1; for M = W, n = 1 to 6) in CH2Cl2 affords the mono(3-hexyne) complexes [MI2(CO)fPh2P(CH2)nPPh2g(2-EtC2Et)] (5 - 11). The tungsten complex [WI2(CO)fPh2P(CH2)3PPh2g(2-EtC2Et)] (8) has also been crystallographically char- acterised and has cis-phosphorus atoms in the equatorial plane with the carbonyl and one of the iodo-ligands, with the other iodo-ligand and the 3-hexyne occupying the axial sites.
* Reprint requests to Dr. P. K. Baker or Dr. M. G. B. Drew.
