Pentagonal bipyramidal complexes

CTP (capped trigonal prism) complexes all the others are the PBP (pentagonal-bipyramidal) complexes. 

The first pentagonal bipyramidal complex of zinc, ZnLCl2 3H20, was reported in 1973, where L is the planar five-coordinate 2,6-diacetylpyridinebis(semicarbazone).346 The crystal structure determination shows the complex to contain the [LZnG(H2Q)]+ cation, with three bland two O-donor atoms forming a slightly distorted planar pentagon around the metal ion and the chlorine and water in axial positions. 

Pentafluoropyridine, with Ni(0) complexes, 8, 47 -8 Pentagonal bipyramidal complexes, triiron complexes, 6, 310 Pentahapto germolyl complexes, with Hf(IV), 4, 987-989 Pentahapto siloyl complexes, with Hf(IV), 4, 987-989 Pentakis(acetoxymercurio)pentamethylruthenocene, preparation, 6, 630... 

The only other example of a Schiff base condensation with dipyridine to form a macrocyclic complex has been reported by Tasker et al.112) in which 2,6-diformyl-pyridine or 2,6-diacetylpyridine is condensed with 6,6 -dihydrazmo-2,2 -dipyridine (132) in the presence of zinc(II) to afford a pentagonal bipyramidal complex 133. The rigidity of the system results in an equatorial Ns donor set that is essentially planar water molecules occupy the axial positions. 

Pentagonal bipyramidal + complex (//-8-coordination Snn[Cn(EDTA)H20H20... 

Zr1, Hf1, d3 1 Zr11, d2 J 7 Pentagonal bipyramidal Complex sheet and [Zr(CO)5(SnMe3)2]2-[ cluster stmctures see text... 

Three coordination is very rare and has been observed in stericaUy hindered phosphine and amide complexes of type [Ni(PPh3)3], [Ni(NPh2)3]A and [(R2N)Ni(M -NR2)2Ni(NR2)]. Seven coordination, although rare, is observed in pentagonal bipyramidal complexes incorporating pentadentate chelate and macrocyclic complexes, for example, [Ni(14)(L)2] and [Ni(15)(L)2]2+. ... 

Treatment of M2C1i0 with 4 eq substituted 2-aminopyridines in tol or under melt conditions produced pseudo-pentagonal bipyramidal complexes bis(amidopyridine)MCl3 (Scheme 8).89-92... 

The peroxo-complexes provide further examples of the ability of oxygen to coordinate to the metals in their high oxidation states. The production of blue solutions when acidified dichromates are treated with H2O2 is a qualitative test for chromium. The colour arises from the unstable CrO. which can, however, be stabilized by extraction into ether, and blue solid adducts such as tCrOs(py)] can be isolated. This is more correctly formulated as lCr0(02>2py] and has an approximately pentagonal pyramidal structure (Fig. 23.6a). Bidenlate ligands, such as phenanlhroline and bipyridyl produce pentagonal bipyramidal complexes in which the second N-donor atom is loosely bonded irons to the =0 (Fig. 23.6b). This 7-coordinate structure is favoured in numerous peroxo-complexes of Mo and W, and the dark-red peroxo anion [Mo(02)4] is 8-coordinate, with Mo-O 197 pm and 0-0 155 pm. 

Vanadium compounds, mainly square pyramidal complexes of the type [0=V(0—R—0)2], act as insulin mimetics with potential in diabetes control if toxicity issues can be overcome one is in use as an orally-administered agent in animals. A pentagonal bipyramidal complex of manganese(II), CMnC A ], where N5 is a pentaaza macrocycle with four amine nitrogen donors and one pyridine nitrogen donor, acts as a... 

A number of monomeric, pentagonal bipyramidal complexes of the type [0=Mo(S2)2(L) have been reported. The complex with L = 2,2-bi-pyridyl 118a) is obtained from MoO " and aqueous S in the presence of 2,2-bipyridyl. The corresponding W complex also is known and has been structurally characterized 118b). A similar complex with L = mOnothiooxalate ( 2038) has been isolated 119) serendipitously by the reaction of Cs2[Mo204(C204)2(H20)2] 2H2O with 082(820202). 

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