Selenide ligands

Goodall (53) has synthesised a series of sulphur and selenium containing ligands related to the ligands used by Kouwenhoven. These are the sulphide and selenide ligands shown in Fig. 39. 

Sulfur and Heavier Group VI Ligands 25.2.4.5.1 Sulfur and selenide ligands... 

Complexes have been prepared with more highly substituted, and also with chelating sulfide and selenide, ligands. Since intramolecular inversion through sulfur is sufficiently slow to be observed on the NMR time scale, the thrust of much of this work has been to understand this inversion process better. 

The solution phase geometry of complexes containing diorgano selenide ligands has been found to be amenable to examination by IR and H NMR spectroscopy, and dipole moment measurements. 

A number of metal complexes with bidentate phosphine selenide ligands, e.g. Ph2P(Se)(CH2) -P(Se)Ph2 (k = 1 or 2), have been reported but, unlike the monodentate phosphine selenides, have yet to be successfully characterized by X-ray crystallography. The coordination of selenium in these types of ligands is amenable to examination by inspection of the vPS vibration in the IR spectra.29,30... 

It is also pertinent to mention the occurrence of bridging phosphido and arsenido selenide ligands (Scheme 4).32 The phosphido selenide complexes (1 Scheme 4) were found to be very reactive and readily gave the six-membered heterocyclic complexes (3). In contrast the arsenido selenide systems gave both the four-membered ring intermediates (1 M = Mn, Re) and the six-membered heterocycles (3). 

The situation with complexes of o-selenide ligands 491, even though such compounds are supposedly well known, is still unclear [636]. The structural details of coordination compounds of phenoselenoazine 492 have not yet been studied in detail [636] ... 

Ni and Se is observed in the structure of the mixed selenide/selenolate cluster [Ni2oSei2(SeMe)io] (7, Figure 13.5) [29]. The cluster contains a Ni2oSei2 core that is stabilized by surface Me groups bonded to Se centers. The interstitial selenide ligands (Se ) arise from Se-C bond scission reactions of the MeSe reagent. 

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