QUADRUPLY BONDED DIMOLYBDENUM COMPOUND WITH BRIDGING PYRIMIDINETHIOL LIGANDS

The reaction of dimolybdenum tetraacetate with the sodium salt of 4,6-dimethyl-2-mercaptopyrimidine (Hdmmp) affords Mo2(dmmp)4. Recrystallization from dichloromethane solution by slow addition of hexane gave mainly acicular crystals of Mo2(dmmp)4.2CH2Cl2, but also some rectangular crystals of Mo2(dmmp)4.CH2Cl2. The structure of one of the latter crystals was determined. The space group was P21/n, and the unit cell had the following dimensions: a = 10.927 (2) Å, b = 10.660 (2) Å, c = 28.149 (5) Å, β = 101.36 (2)°, V = 3214 (1) Å3. With Z = 4, the formula unit is the asymmetric unit. The structure is of the expected general type. It has a ligand arrangement with two trans S atoms and two trans N atoms on each molybdenum. The Mo-Mo bond length, 2.083 (2) Å, is slightly longer than those in the four other molecules containing quadruply bonded Mo24+ and ligands of the same general class. Other bond lengths and angles have values that are not surprising in comparison with those in comparable molecules. © 1979, American Chemical Society. All rights reserved.