Received 24 September 2008
The title compound, [Mo4(C16H20)2O8]·6H2O, is a centrosymmetric ansa-molybdocene complex in which two dinuclear [C2Me4(5-C5H4)2]Mo(2-O)2MoO2 units dimerize by forming two 3-O bridges between three Mo atoms. The ansa-molybdocene [C2Me4(5-C5H4)2]Mo unit has a typical bent-sandwich metallocene structure with an inter-ring angle of 127.98 (8)°. The Mo atom in the bridging (2-O)(3-O)2MoO2 group has a distorted trigonal-bipyramidal coordination. The Mo-(3-O) and Mo-(2-O) bond distances inside the units [2.0869 (14) and 2.1014 (15) Å, respectively] are slightly longer than the Mo(-x + 1, -y + 1, -z)-(3-O) bond distance between the units [1.9986 (14) Å]. The solvent water molecules together with complex O atoms form a network of O-HO hydrogen bonds.
For related structures, see: Prout & Daran (1978); Adam & Green (1981); Daran & Prout (1977); Prout et al. (1974). For general synthesis and reactivity information on related tetramethylethylene-bridged ansa-molybdocene complexes, see: Ahmed et al. (2007).
Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: HB2806 ).
We thank the NSF for funding.
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