Quinquedentate ligands

The structure of rac-[Co(trenen)N3](N03)2,H20 [trenen = 4-(2-amino-ethyl)-l,4,7,10-tetra-azadecane] has been determined. The complex is octahedral and the quinquedentate ligand forms Co—N bonds of almost identical length [1.95(6)—1.964(5) A]. 2i... 

The potentially quinquedentate ligands (58) have been prepared and the complexes [Fe(L — 2H)C1] obtained, in which the chloride ion is definitely co-ordinated. However, it was not possible to make a definite structural assignment to either five-or six-co-ordination.294 The related ligand (59) also forms an [Fe(L — 2H)C1]... 

An X-ray structural analysis of the compound [Mn(L)(NCS)] (where L = (161), X = (CH2)3— NH—(CH2)3 and Y is a fused C6H4 ring) shows an octahedral Mn111 atom, with the NCS group and the central N atom of the quinquedentate ligand occupying the apical positions.658... 

The planar quinquedentate ligand 2,6-diacetylpyridine bis(semicarbazone), D APSC, has been synthesized and used to prepare the complex [(H20)2(DAPSC)Cr]-0H(N03)2,H20. The two water molecules occupy axial positions in the pentagonal bipyramid. It is suggested that the characterization of this stereochemistry for chro-mium(iii) may imply a possible role for seven-co-ordinate species as intermediates in octahedral substitution reactions. ... 

NO2 and 5-NO2, 5-Cl and 5-Me complexes are low spin, the others showing a spin equilibrium. The planar quinquedentate ligand, 2,6-diacetylpyridine bis-(semi-carbazone) (DAPSC) forms the complex [FeCl2(DAPSC)]Cl,2H20 in which the... 

A subsequent study by Shu and Rorabacher [122] has been directed at outer-sphere effects in methanol—water mixtures. To reduce inner-sphere effects to a minimum, a quinquedentate ligand (N-hydroxyethylethylene-diamine-N,N, N -triacetate, HEEDTA) was complexed to Ni(II) leaving a single coordination site available for ammonia—solvent exchange... 

Pyridine and related ligands. The crystal structures of [M(py)2(N03)2] (M = Co, Cu, or Zn) have been determined and the overall molecular geometries are very similar for all three compounds. In all of these complexes the nitrate groups are co-ordinated in an assymetric bidentate manner, the degree of assymetry following the order Co < Zn Cu. Cobalt complexes of the linear quinquedentate ligand pyDPT (75) have been isolated. They are [Co-(pyDPT)X]X,H20 (X = Cl, Br, 1, or NO3), [Co(pyDPT)](PF6)2, and... 

Reaction of (64) with Co(OAc)2,4H20 in ethanol produces a cobalt(ii) chelate. The potentially quinquedentate ligands iVN -bis(salicylidene)-2,2 -bis(aminoethyl)sulphide and its 5-bromo, 5-methyl, 5-nitro, and 3-iso-propyl derivatives form neutral tetrahedral cobalt(ii) complexes." 2-(o-Hydroxyphenyl)benzothiazoline reacts with cobalt(ii) salts in a 2 1 molar ratio to form chelates of o-H2NCgH4.SN however, 2-phenylbenzothiazoline... 

Comparison of base hydrolysis, racemisation, and proton exchange rates for [CoX(trenen)] +, where X = Cl , N3-, or OHg, and trenen is the quinquedentate ligand (19) indicates an nlcb mechanism for base hydrolysis. The demonstration of linear free energy plots (AG vs. AC ) of... 

The Cr(III) and Mn(II) complexes with a ligand derived from 3,3 -thiodipropionic acid have been synthesized and characterized by elemental analysis, molar conductance measurements, magnetic susceptibility measurements, IR, UV, and ERR spectral studies. The complexes are found to have [Cr(L)X]X and [Mn(L)X]X, compositions, where L = quinquedentate ligand and X=NO, Cl and OAc. The complexes possess the six coordinated octahedral geometry with monomeric compositions. The evaluated bonding... 

The quinquedentate ligand (31a) occurs in the neutral dimeric complex (31b) in which two octahedrally co-ordinated cobalt atoms related by a crystallographic Cj axis are linked through a peroxide bridge. In the Co-O-O-Co bridge the 0-0 bond length is 1.45(2) A and the torsion angle... 

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