Molybdenum, nitrosyl

A series of polyether macrocycles [59]—[66] (Fig. 33) that contain a coordinated reducible, redox-active 16-electron molybdenum nitrosyl (Mo(NO)(3+ group have been prepared (Al-Obaidi et al, 1986 Beer et al., 1987). Compounds [59]—[63] were synthesized from the reactions between [Mo(NO)LX2] (L = tris(3,5-dimethylpyrazolyl)hydroborate X = Cl or I ) and the appropriate amine substituted benzo-crown ether. Compounds... 

Complexes of Other Metals. Having studied in detail catalysts derived from molybdenum nitrosyl complexes, it was interesting to investigate the effect on catalytic activity of substituting other transition metals in both nitrosyl derivatives and in other related complexes. 

An extensive series of molybdenum nitrosyl complexes have been prepared which are very active in the presence of a cocatalyst, e.g. [Mo(NO)2(OEt)2]/EtAlCl263-73. 

These complexes can also be used to prepare optically pure cis-2,5-disubstituted 5,6-dihydro-2tf-pyrans such as 3 by using a molybdenum nitrosyl allyl complex as an intermediate. 

The electrochemical transformation of a molybdenum nitrosyl complex [Mo(NO)(dttd)J [dttd = 1,2-bis(2-mercaptophenylthio)ethane] (30) is rather interesting (119). Ethylene is released from the backbone of the sulfur ligand upon electrochemical reduction. The resulting nitrosyl bis(dithiolene) complex reacts with O2 to give free nitrite and a Mo-oxo complex. Multielectron reduction of 30 in the presence of protons releases ethylene and the NO bond is cleaved, forming ammonia and a Mo-oxo complex (Scheme 15). The proposed reaction mechanism involves successive proton-coupled electron-transfer steps reminiscent of schemes proposed for Mo enzymes (120). 

Bimetallic molybdenum nitrosyl complexes, (containing Mo(I), i.e. a 17e species) with conjugated bridging ligands of the bispyridine family, or the bisphenolate family, present widely separated reduction waves, as shown by McCleverty, Ward, and others [86], The separation can be observed with spacers containing up to four double bonds, or four phenylene units. 

Molybdenum Nitrosyl Complexes Containing Bridging Hydrazido Groups X-Ray Analysis of the Structure of [(7t-C5H5)Mo(NO)I]2(Ai-NNMe2), W. G. Kita, J. A. McCleverty, B. E. Mann, D. Seddon, G. A. Sim, and D. I. Wood-house, Chem. Commun., 1974, 132. 

Dybov A, Blacque O, Berke H (2011) Molybdenum nitrosyl complexes and their application in catalytic imine hydrogenation reactions. Eur J Inorg Chem 652-659... 

However, by development of the chemistry of the kinetically and thermodynamically stable dinuclear tris(3,5-dimethylpyrazolyl)borato molybdenum nitrosyl and oxo complexes, it has been possible to perform combined studies of electronic and magnetic interactions. The purpose of this case study is to illustrate how a wide variety of physical methods has been used in this area, and to show how, in these complexes, the electronic and magnetic interactions—despite being quite different phenomena—share the same relationship to the structure of the bridging ligand. 

Figures 7,8 shows plots of data for chromium and molybdenum nitrosyl species the slope with El(L) is essentially the same as for non-NO species. Thus, in Figure 7,8 [data from 10,31,32], a value for El(NO) is used which will cause the nitrosyl complexes to fit the correlation line. This yields El(NO + ) = 2.55 - 2.57 for both metal ions. Values in the range 1.2 -1.8, for El(NO" "), have been described by Clarke [33] for some technetium nitrosyl derivatives. This area would benefit from a detailed analysis.

Electrochemical Transformation of the Molybdenum Nitrosyl [Mo(NO)Cl(dttd)] dttd = l,2-bis(2-... 

Key words Molybdenum, nitrosyl, pyrazolylborate, electrochemistry, cyclic polyether, complexation, sodium, potassium. 

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