Trigonal bipyramidal geometry molecular

When there are five electron groups around the central atom, it is sp d hybridized. AB5 molecules and ions with no lone pairs on the central atom have trigonal bipyramidal electronic geometry, trigonal bipyramidal molecular geometry, and sp d hybridization on the central atom. 

C09-0129. Tellurium compounds, which are toxic and have a hideous stench, must be handled with extreme care. Predict the formula of the tellurium-fluorine molecule or ion that has the following molecular geometry (a) bent (b) T-shaped (c) square pyramid (d) trigonal bipyramid (e) octahedron and (Q seesaw. 

The Lewis formula predicts 5 electron groups around the central Br atom and a trigonal bipyramidal electronic geometry. There are two lone pairs on the Br atom, so the molecular geometry is T-shaped (Section 8-11). 

The Lewis formula shows 5 electron groups around the central S atom and its electronic geometry is trigonal bipyramidal. The molecular geometry is a seesaw due to the presence of 1 lone pair of electrons on the central S atom. 

Sharma and Reed, 1976)]. In proteins the coordination number 4 is most common, where the zinc ion is typically coordinated in tetrahedral or distorted tetrahedral fashion. The coordination polyhedron of structural zinc is dominated by cysteine thiolates, and the metal ion is typically sequestered from solvent by its molecular environment the coordination polyhedron of catalytic zinc is dominated by histidine ligands, and the metal ion is exposed to bulk solvent and typically binds a solvent molecule (Vallee and Auld, 1990). The inner-sphere coordination number of catalytic zinc may increase to 5 during the course of enzymatic turnover, and several five-coordinate zinc enzyme—substrate, enzyme product, and enzyme-inhibitor complexes have been studied by high-resolution X-ray crystallographic methods (reviewed by Matthews, 1988 Christianson and Lipscomb, 1989). The coordination polyhedron of zinc in five coordinate examples may tend toward either trigonal bipyramid or octahedral-minus-one geometry. 

Values of umn, umx and uM for synunetrical tetrahedral (MZ3), trigonal bipyramidal (MZ4), and octahedral (MZ5) groups can be obtained from Eq. 17 using the rv values calculated from Eq. 1-3 and 6-10. Values of rV mn, rv,mi and rV-ax for symmetrical bicycloalkyl and heterobicycloalkyl groups can be calculated from molecular geometry. The appropriate values are then obtainable from Eq. 17. 

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