Trans effect complex

Pt(II) metal complexes, are known to exhibit a structural trans effect. In octahedral complexes, trans effects can also occur, even if these effects are less pronounced... 

The complexes frans-[Ru(NH3)4 P(OR)3 2] and trans-[Ru(NH3)4 P(OEt)3 P(OR)3 ], with R = methyl, isopropyl, or butyl, aquate to give a monophosphite product with rate constants which vary little with the nature of the complex or solvent composition (up to 80% ethanol). The results support the dissociative mechanism previously proposed for the triethyl phosphite complex. Trans effects are here dominated by 7T acceptor properties of these phosphite ligands. Trans effects in substitution in bis-ligand ruthenium (and iron) phthalocyanine complexes follow the order... 

Similarity with cobalt is also apparent in the affinity of Rh and iH for ammonia and amines. The kinetic inertness of the ammines of Rh has led to the use of several of them in studies of the trans effect (p. 1163) in octahedral complexes, while the ammines of Ir are so stable as to withstand boiling in aqueous alkali. Stable complexes such as [M(C204)3], [M(acac)3] and [M(CN)5] are formed by all three metals. Force constants obtained from the infrared spectra of the hexacyano complexes indicate that the M--C bond strength increases in the order Co < Rh < [r. Like cobalt, rhodium too forms bridged superoxides such as the blue, paramagnetic, fCl(py)4Rh-02-Rh(py)4Cll produced by aerial oxidation of aqueous ethanolic solutions of RhCL and pyridine.In fact it seems likely that many of the species produced by oxidation of aqueous solutions of Rh and presumed to contain the metal in higher oxidation states, are actually superoxides of Rh . ... 

In the case of the trans-complex, only the two chloride ions are substituted, the trans-effect of ammonia being too low to give substitution with the result that white needle crystals of trans-[Pt(NH3)2(tu)2]Cl2 are formed [73],... 

Kinetic study [141] of complexes of the type trans-Pt(PEt3)2XCl was of great value in establishing the strong trans-effect of hydride (Table 3.13) examination of the data for a wide range of reactions gives rise to a series... 

A seminal paper [155] examined platinum-phosphorus NMR coupling constants in a series of cis- and trans-platinum(II and IV) complexes. The trans-influence had hitherto been explained in terms of d7r-p7r bonding, in other words, such a mechanism dominated with trans-effect... 

Application of the trans-effect to synthesis ofplatinum( IV) complexes... 

Like the isoelectronic Pd2+ and Pt2+, Au3+ exhibits both trans-effects and trans-influence. Table 4.13 (above) lists structural data for a number of complexes AuL3L, showing how the disparity in Au-X distances between cis-and trans-X depends on the position of L in the trans-effect series for the compounds listed, the effect is least noticeable in AuC13NH3 as these two ligands are proximate in the series. 

DNA polymerases, 5, 1007 Trans effect, 1,16, 26, 315 metal complexes, 2, 705, palladium(II) amine complexes, 5, 1115 platinum complexes, 5, 353, 493 six-coordinate compounds. 1, 49 T ransestcrification metal alkoxide synthesis, 2, 340 Transferases zinc, S, 1002... 

H. W. Quinn and J. H. Tsai Cis and Trans Effects in Cobalt(Ill) Complexes... 

As the trans effect theory indicates, there should be some relationship between lability of a ligand and its role as a labilizing group in another position in a complex. In an octahedral complex reacting via a dissociative mode of activation, the transition state has five strongly bound ligands. This state will be stabilized... 

Thiocarbamate (tc, RHNCSO-) is a monodentate ambidentate ligand, and both oxygen- and sulfur-bonded forms are known for the simple pentaamminecobalt(III) complexes. These undergo redox reactions with chromium(II) ion in water via attack at the remote O or S atom of the S- and O-bound isomers respectively, with a structural trans effect suggested to direct the facile electron transfer in the former.1045 A cobalt-promoted synthesis utilizing the residual nucleophilicity of the coordinated hydroxide in [Co(NH3)5(OH)]2+ in reaction with MeNCS in (MeO)3PO solvent leads to the O-bonded monothiocarbamate, which isomerizes by an intramolecular mechanism to the S-bound isomer in water.1046... 

The preparation of the dinuclear complexes is readily achieved by taking advantage of the well-established trans effect in square-planar complexes. For example, the treatment of two equivalents... 

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