Investigations of the coordination chemistry of molybdenum with facultative tetradentate ligands possessing N2S2 donor sets. 4. Crystal and molecular structures of [Mo2O3(C8H18N2S 2)2] and [Mo2O4(C9H22N2S 2)2]

P. L. Dahlstrom, J. R. Hyde, P. A. Vella, Jon A Zubieta

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Abstract

The reaction of [MoO2(acac)2] with a twofold excess of N,N′-dimethyl-N,N′-bis(β-mercaptoethyl)ethylenediamine (LH2) gives the deep purple compound [Mo2O3(C8H18N2S 2)], [Mo2O3L2], in low yield. X-ray crystallography shows that the molecule possesses a trans planar [O=Mo-O-Mo=O]4+ core and that the ligand is present as a tetradentate, coordinating through sulfur and nitrogen donors. The complex crystallizes in space group Pcab with cell parameters a = 15.318 (3) Å, b = 17.957 (4) Å, and c = 18.298 (4) Å. The measured density of 1.70 g/cm3 was in good agreement with the value of 1.72 g/cm3 calculated on the basis of eight molecules in the unit cell. The structure has been refined to R1 = 0.042 and R2 = 0.048 on the basis of 2413 unique reflections with Fo ≥ 6σ(Fo). The analogous reaction of [MoO2(acac)2] with the ligand N,N′-dimethyl-N,N′-bis(β-mercaptoethyl)propylenediamine (L′H2) yields orange prisms of the compound [Mo2O4(C9H22N2S 2)2], [Mo2O4(L′H)2]. The complex crystallizes in the monoclinic space group P21/a with unit cell dimensions a = 15.155 (5) Å, b = 12.446 (5) Å, and c = 16.195 (6) Å, and β = 101.99 (1)° with Z = 4 to give a calculated density of 1.55 g/cm3 (observed density 1.54 g/cm3). The structure was solved on the basis of 1907 unique reflections with Fo ≥ 6σ(Fo) and refined to final R values of 0.059 and 0.083. The complex possesses the Mo2O4 2+ core with molybdenum atoms coordinating to the thiolate sulfurs of the L′ ligand. The unusual feature of the structure is that the two ligand amine nitrogens are not coordinated to the molybdenum, resulting in the 14-membered ring (CH2)3N(CH2)2SMoOMoS(CH 2)2N. One of the L′H nitrogens is protonated to produce a six-membered H-N-C-C-C-N ring with a chair conformation, and the ligand itself assumes an overall chair conformation.

Original languageEnglish (US)
Pages (from-to)927-932
Number of pages6
JournalInorganic Chemistry
Volume21
Issue number3
StatePublished - 1982
Externally publishedYes

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ASJC Scopus subject areas

  • Inorganic Chemistry

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