Trigonal pyramidal species

Tolman and co-workers investigated the oxygenation behavior of a copper(I) complex (790) (trigonal pyramidal) and demonstrated the formation of end-on peroxo-dicopper(II) species.58... 

B. Formation of an intermediate species with prior or subsequent breaking of one metal oxygen bond (probably to form a trigonal pyramid intermediate) followed by loss of a proton and reformation of the stable chelate ring. 

Basal CN. b Apical CN. 5 Distorted trigonal bipyramidal species. d Square pyramidal species. 

There are four electron pairs around carbon in CH3 they are arranged in a tetrahedral fashion. The atoms of this species are in a trigonal pyramidal arrangement. 

Metal disulfides (MS2) and metal dichalcogenides (MS4) (metal M = Cd, Mo, Zr, Ti, Nb, Ta, or Sn) are lamellar colloids with strong M—S bonds within the layers and weak van der Waals interactions between the layers. Each metal atom in these lamellae is surrounded by six sulfur anions with an approximate octahedral coordination geometry. Each sulfur anion is, in turn, coordinated to three metal atoms with a trigonal pyramidal geometry [50], Certain cationic species or polymers are adsorbed onto these surfaces via intercalation or exfoliation [51,52],... 

Reeves, 1965), pyramidal species (Koeppl et al., 1967), aziridines (Anet and Osyany, 1967), azo compounds (Talaty and Fargo, 1967), imines (Curtin et al., 1966), some trigonal bipyramids (Muetterties and Schunn, 1966), etc. are known, similar energies for radicals, carbanions, car-bonium ions, are generally unavailable. 

A series of air-sensitive trigonal bipyramidal and trigonal pyramidal Ni complexes, [Ni(PR3)4]+, [NiX(PR3)3], [NiX(AsR3)3] (X = halide), and [Ni(tripod)]+ and [NiX(tri-pod)] (tripod = face-capping tripodal P, As ligand), have been reported. The methods of synthesis of these species are varied, but essentially are based on the reduction of Ni or oxidation of Ni precursors. A range of four- and five-coordinate Ni complexes have been stmcturally characterized and some of these are illustrated in (42)-(46). 

Se2Br5+, as the first reported example of a novel dinuclear cationic halogen-chalcogen species, was prepared as the deep-purple crystalline hexafluoroarsenate. The cation consists of two trigonal pyramidal SeBrs units connected via a linear Se-Br-Se bridge. The formally positive Br+ links two SeBr2 molecules with formal oxidation number - -2 for Se. 

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