Thionitrosyl

H. W. Roesky and K. K. Pandey, Transition-Metal Thionitrosyl and Related Complexes, Adv. Inorg. Chem. Radiochem., 26, 337 (1983). 

A variety of routes is available for the preparation of metal-thionitrosyl complexes. The most common of these are (a) reaction of nitride complexes with a sulfur source, e.g., elemental sulfur, propylene sulfide or sulfur halides, (b) reaction of (NSC1)3 with transition-metal complexes, and (c) reaction of [SN]" salts with transition-metal complexes. An example of each of these approaches is given in Eq. 7.1,... 

The nitrogen atom in the (almost) linear metal-thionitrosyl complexes is 5p-hybridized and the NS ligand behaves as a three-electron donor. The N-S bond distances in metal complexes vary between 1.45... 

The thionitrosyl group may be stabilized either by a dimethylamino substituent or by the use of a highly bulky ort/io-substituted aryl groups. Ai,A -Dimethylthionitrosoamine M2NNS is obtained as a low melting, deep purple solid from the reaction of 1,1-dimethylhydrazine with sulfur (Eq. 10.1) or by the reduction of Mc2NNSO with LiAlH4. This thermally unstable derivative is monomeric in solution. 

First thionitrosyl (NS) complex isolated by J. Chatt and J. R. Dilwonh. 

In contrast to the numerous complexes of NO which have been prepared and characterized, complexes of the thionitrosyl ligand (NS) are virtually unknown, as is the free ligand itself. The first such complex [Mo(NS)(S2CNMc2)3] was obtained as orange-red air-stable crystals by treating [MoN(S2CNMe2>3] with sulfur in... 

Thionitrosyl complexes have already been briefly mentioned on p. 453 and have recently been reviewed.They were first made " by reacting azido complexes directly with... 

A few thionitrosyl complexes have been synthesized. MO calculations suggest that NS is a superior <7-donor and 7r-acceptor to NO [128], Syntheses include... 

The structure of this compound shows a roughly linear thionitrosyl linkage (Ru-N—S 171°) with a rather short Ru-N bond (1.729 A). 

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