Ligands, quadridentate trigonal bipyramidal

A range of complexes with the novel quadridentate and tridentate ligands (53 L = P or As, or mixed P, As) and (54 L = P or As) have been prepared and characterized by lH n.m.r. and u.v.-visible spectroscopy,232,233 Trigonal-bipyramidal or octahedral compounds were generaly obtained, for example, the species [IrX (o-... 

Chloro and iodo complexes of the quadridentate ligands (102), (103) and (104) have been prepared. No preparative details are available and the complexes are all too insoluble to confirm the speculation that they are trigonal bipyramidal.1059... 

An X-ray crystal structure determination of the triptych compound 62 revealed the trigonal bipyramidal coordination geometry, which is schematically shown in Fig. 17, with the three carbon atoms at the equatorial sites and the coordinating nitrogen atom and the chlorine atom at the axial positions. As a result of the fixed geometry of the quadridentate tris-anionic ligand, the Sn—N coordination bond (2.37(3) A) is extremely short 125). 

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