Ligand geometry

Diiminatc zinc complexes are highly active catalysts in the copolymerization of epoxides and C02. Complexes that are catalytic are of the form ZnLX, where X is alkoxide, acetate, or bis(tri-methylsilyl)amide. Changing the ligand geometries of the complexes allows variation in the catalytic behavior and activity.941 The polymerization of lactide with diiminate zinc has also been studied.942... 

Hdft, E. Enantioselectivc Epoxidation with Peroxidic Oxygen. 164, 63-77 (1993). Hoggard, P. E. Sharp-Line Electronic Spectra and Metal-Ligand Geometry. 171, 113-142... 

All borabenzene-metal complexes investigated structurally so far show very similar patterns for the ligand geometry (Table I) and for the metal-ligand bonding (Table II) only the cobalt complex 6 deserves separate consideration (see below). 

Figure 6b. An outline diagram of the macropolyhedral borane ligand geometry and its interaction with the Pt center C8j.

The unusual fluorocarbon ligand geometry reported last year for [(AsMe2-CF2CFHAsMe2)Cr(CO)4] and related compounds are incorrect. The X-ray data and chemical properties of the compounds are better interpreted in terms of a disordered arrangement of molecules with normal geometries and dimensions. The ditertiary arsine chelates (53) have been synthesized by the... 

The formation of inclusion complexes is influenced mainly by steric parameters of ligands (geometry and size) and by the possibility of creating hydrophobic interactions and hydrogen bonds (physicochemical properties). Hydrophobic interactions predominate in the cavity, and they can act in concert with polar interactions that occur with hydroxyl groups located at the outer lip of the CDs. There are no covalent bonds (14). 

---