Preparation of the new species [W 3(μ 3-O)(μ-Cl) 2(μ-O 2CMe) 4Cl 3] − and [Mo 3(μ 3-O)(μ-Cl) 4(μO 2CMe) 2Cl 2(PMe 3) 2] − that bracket, structurally, the very common M 3(μ 3-O)(μ-X) 3(μ-O 2CR 3) 3L 3 type of cluster compound

Abstract

Two new monocapped trinuclear molybdenum and tungsten clusters, which also contain different numbers of bridging halogen atoms and carboxylate groups, have been synthesized and characterized by X-ray diffraction, thus completing an entire series of monocapped trinuclear molybdenum and tungsten clusters with 1–6 bridging carboxylate ligands. Compound 1, (Et 4N)[W 3OCl 5(OAc) 4]·3CH 2Cl 2, was obtained as a byproduct in the reaction of (Et 4N) 3[W 2Cl 9] with acetic acid and acetic anhydride. Crystallographic data: space group P2 12 12 1, a=12.795(3), b=15.685(3), c=19.436(3) Å, V=3901(1) Å 3, Z=4, R=0.037. The W-W distances are 2.7280(7), 2.5754(8) and 2.5715(8) Å. The average oxidation state of the tungsten atoms is +3.33. Compound 2, (Et 4N)[Mo 3OCl 6(OAc) 2(PMe 3) 2], was synthesized by the reaction of (Et 4N)[Mo 3OCl 6(OAc) 3] with Me 3SiCl and PMe 3 in THF. Crystallographic data: space group Pna2 1, a=27.459(7), b=13.660(5), c=18.524(5) Å, V=6948 Å 3, Z=8, R=0.052. The Mo-Mo distances are 2.627(4), 2.546(3) and 2.631(6) Å. The entire series of monocapped trinuclear molybdenum and tungsten clusters with 0–6 μ-CH 3CO 2 groups is reviewed.