The Molecular Structure of a Diamagnetic, Doubly Oxygen-Bridged, Binuclear Complex of Molybdenum(V) Containing a Metal-Metal Bond

Abstract

The crystal and molecular structure of the compound BaMo04(C204)2 • 5H20 has been determined by a single crystal X-ray diffraction study. It is found to contain a binuclear anion, {[MoO(C204)H20]202}2-, oxalatooxoaquomolybdenum(V)-µdioxo-oxalatooxoaquomolybdenum(V). The idealized structure consists of two octahedrally coordinated molybdenum atoms sharing an edge. The two halves are related by a (crystallographic) twofold rotation axis passing through the center of the Mo<q>Mo ring. The Mo-Mo distance of only 2.541 Á. suggests that the diamagnetism of the compound is due to an Mo-Mo bond.(5) W. G. Sly, D. P. Shoemaker, and J. H. Van den Hende, "I.B.M. 709/ 7090 Fourier Program, '' 1962.

Structural studies of molybdenum amino-acid complexes: the crystal and molecular structures of hydrogendi(bis-π-cyclopentadienyl)-L-cysteinatomolybdenum(IV) chloride, hydrogendi(bis-π-cyclopentadienyl)-L-cysteinatomolybdenum(IV) hexafluorophosphate, bis-π-cyclopentadienylglycinatomolybdenum(IV) chloride monohydrate and bis-π-cyclopentadienylsarcosinatomolybdenum(IV) chloride methanolate

“…The Mo-S bonds in the cysteine complexes (2.446 in cysteine-Cl and 2.45 and 2.48 A in cysteine-PF6) are not significantly different from those observed in the molybdenum(V) complexes bis-n-cyclopentadienyl(toluene-3,4-dithiolato)molybdenum (2.434 and 2.431 t~,) (Knox & Prout, 1969b), bis-n-cyclopentadienyl)molybdenum iron(ll)dichloride (Cameron & Prout, 1972a), but significantly shorter than the Mo(V)-S bond (2.490 A) in the oxomolybdenum(V) cysteine complex (Knox & Prout, 1969c). The Mo-O bond in glycine-C1 and sarcosine-C1 are identical in length (2.10 and 2.10 .~), and in very good agreement with 2.11 and 2.15 A Mo-O (oxalato) bonds in the Mo(VI) complex BaMozO4(CzO4)z(HzO)z (Cotton & Morehouse, 1965). The X-Mo-X angles, cysteine-C1 77.0 °, cysteine-PF6 80 and 78 °, glycine-Cl 74.1 ° and sarcosine-Cl 73.4 ° are less than those found in the complexes with sulphur or chlorine ligands (Green, Green & Prout, 1972) but comparable to the angle of 75.7 ° found in (n-CsHs)zMo(OH)NHzCHJ (Prout, Critchley & Forder, 1972).…”

Spectral and Thermal Studies of Some Binuclear Dimeric Mo-O-Mo Bridged Oxomolybdenum(V) Complexes with Bis(carboxamides) Derived from 4,4’-Diaminobiphenyl, 1,4-diaminobenzene with Anhydrides

“…Which has been attributed to a transition involving the Mo-O-Mo bridge. This interpretation has been previously proposed to explain the origin of similar bands in the electronic spectra of analogous xanthate and dithiocarbamate dimmers [16][17][18][19][20][21] . The electronic spectrum shows a shoulder in the region ca.…”

Disodium μ-(Ethylenediaminetetraacetato-N,O,O':N',O'',O''')-di-μ-oxo-bis[oxomolybdate(V)](Mo—Mo) Tetrahydrate

“…They are also comparable to the value of 2. i 2 A found in Ba[Mo2-O4(C,O4)_4HzO)_q (Cotton & Morehouse, 1965). The edta carboxylate groups in the title compound have bond lengths comparable to those found in the carboxylic group of uncoordinated H4edta (Cotrait, 1972).…”

“…There is direct bonding between the two Mo atoms [2.554 (1)/k] which indicates coupling of electron spins on adjacent Mo v ions through metalmetal bonding (Kay & Mitchell, 1968). This bond is comparable to that (2.54 A) in the compound studied by Cotton & Morehouse (1965).…”