Tricoordinated metals

The acute-angle coordinations were similarly predicted for tricoordinated metal complexes [66]. The acute O-Al-O angles of trihydrated aluminum clusters were reported [67]. 

Figure 13.4. Valence orbitals of a tricoordinated metal A (longer gray bracket) is analogous to . The splitting of the upper levels (shorter gray bracket) is a measure of the trans effect.

Figure 13.8. Analysis of alkene binding to different tricoordinated metal complexes.

A tricoordinated metal is highly unsaturated. Relatively stable fragments occur as follows 16e (s d ), structure e.g., Ni(C2H4)3 12e structure C2v, e.g.,... 

Tricoordinated metal complexes should be involved in order to observe a high selectivity [951], The transition-state assembly is envisioned as having an ammonium enolate coordinated to the transition metal through the isocyanate residue 6.132 (Figure 6.104). 

Under the eonditions of erystallization of eopper carbene complex 109, the carbene ligand tends to be retransferred to chromium while the vacant coordination site at copper is occupied by diethyl ether. [98] The X-ray structure of 109 provides a rare example of a tricoordinated metal center. Both copper containing species, the bis-carbene and the mono-carbene 109, undergo a carbene dimerization in the presence of tributylphosphine to yield (l , 3 , 5 )-l,3,5-trienes in a process analogous to the formation of 107. [98]... 

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