Di-μ(3)-oxido-di-μ(2)-oxido-tetra­oxido­bis­(1,1,2,2-tetra­methyl­ethylenedicyclo­penta­dien­yl)­dimolyb­denum(IV)­dimolybdenum(VI) hexa­hydrate

The title compound, [Mo(4)(C(16)H(20))(2)O(8)]·6H(2)O, is a centrosymmetric ansa-molybdocene complex in which two dinuclear [C(2)Me(4)(η(5)-C(5)H(4))(2)]Mo(μ(2)-O)(2)MoO(2) units dimerize by forming two μ(3)-O bridges between three Mo atoms. The ansa-molybdocene [C(2)Me(4)(η(5)-C(5)H(4))(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 (μ(2)-O)(μ(3)-O)(2)MoO(2) group has a distorted trigonal–bipyramidal coordination. The Mo—(μ(3)-O) and Mo—(μ(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)—(μ(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—H⋯O hydrogen bonds.