Notes. Complexes containing mercury–molybdenum bonds: new compounds of the type [HgX{trans-Mo(CO)2L(η5-C5H5)}](L = arsine or phosphine). Crystal and molecular structure of the complex [Hg(CN){trans-Mo(CO)2(AsMe2Ph)(η5-C5H5)}]
Abstract
The series of Hg–Mo bonded complexes [Hg(CN){trans-Mo(CO)2L(η5-C5H5)}](where L = AsMe2Ph, PMe2Ph, PMePh2, or PPh3) have been prepared from Hg(CN)2 and the salts Na[Mo(CO)2L(η5-C5H5)] or dimers [Hg{trans-Mo(CO)2L(η5-C5H5)}2]. The cyanomercury complexes are extremely useful intermediates for the facile synthesis of the derivatives [HgX{trans-Mo(CO)2L(η5-C5H5)}](where X = Cl, Br, I, NO3, O2CMe, OCN, SCN, or S2CNEt2). The molecular structure of the complex [Hg(CN){trans-Mo(CO)2(AsMe2Ph)(η5-C5H5)}] has been determined by single-crystal X-ray analysis. The crystals are monoclinic, space group P21/c, with a= 14.570(4), b= 12.457(3), c= 10.783(3)Å, β= 114.04(2)°, and Z= 4. The structure was solved by heavy-atom methods and refined by least squares to a residual of 0.037 for 2 218 reflections with |I0| > 3σ(I). The Hg–Mo bond length [2.654(1)Å] is the shortest hitherto observed.