Tris methane complexes

The first copper(I) complex of tris(hydroxymethyl)phosphine ((760) tetrahedral) has been reported by Samuelson and co-workers. This group addressed the question of anion-controlled nuclearity and metal-metal distances in copper(I)-bis(diphenylphosphino)methane complexes, and in this endeavor they reported the structures of complexes (761) (Cu-Cu separation 3.005-3.128 A), (762) (Cu-Cu separation 3.165 A) and (763) (tetrahedral Cu-Cu 3.293 A). 6 They synthesized and provided structural evidence of oxy anion- encapsulated copper(I) complexes of this ligand. The complexes (764) (distorted tetrahedral Cu-Cu 3.143 A), (765) (distorted tetrahedral Cu-Cu 3.424A), (766) (distorted trigonal Cu-Cu 3.170A), and (767) (Cu-Cu 3.032-3.077A) were reported. They studied solid-state emission spectra of these complexes.567 During this pursuit they... 

Solution Studies of Tris(pyrazolyl)methane Complexes. 118... 

Although the poly(pyrazolyl)borate complexes of iron(II) have been well known for many years, [1] it is only recently that the complexes with the tris(l-pyrazolylmethane ligand, HC(pz)3, [45-48] have been studied in detail. It should be noted that poly(pyrazolyl)methane ligands, such as the tris(l-pyrazolylmethane ligand, are neutral, whereas the poly(pyrazolyl)bo-rate ligands, such as the tris(l-pyrazolyl)borate ligand, HB(pz)3", are monoanions. As a consequence, the metal(II) poly(pyrazolyl)methane complexes are dications and often have quite different properties from those of the analogous metal(II) poly(pyrazolyl)borate molecular complexes. But, in spite of these differences there are often very close structural similarities between the dicationic complexes and the neutral complexes. Therefore the study of the pyrazolylmethane complexes will parallel that of the borate complexes discussed above. 

Very recently, TiCl( N Bu Xfb Qd IMc2)3C)(TI IF) (23) was prepared via deprotonation of the corresponding tris(pyrazolyl)methane complex TiCl2(NBut)((N2C3HMe2)3CH). This species is the first structurally authenticated sp3-hybridized carbanion derivative.215... 

Figures Tris(pyrazolyl)borate, tris(indazolyl)borate andtris(pyrazolyl)methane complexes...

H/D exchange in TpPt(H)2(CH3) (Tp=hydrido-tris(pyrazolyl)borate) was investigated with the DFT method [24], where various functionals were used. The reaction takes place through the reductive elimination of methane, methane rotation, and the oxidative addition. Important in this reaction is that the platinum(II) methane complex is very stable the binding energy of methane with the Pt(II) center was evaluated to be 6.0 kcal/mol and the activation barrier for methane loss was 11.9 kcal/mol, where mPWlk functional was... 

The conversion of Ught hydrocarbons into value-added functionalized products, under mild conditions, is still a serious challenge, but tris(pyrazol-l-yl)methane complexes of V, Fe, Cu, and Re have already been successfully applied as catalysts or catalyst precursors for relevant alkane oxidation reactions, namely, peroxidative oxygenations (to give alcohols and ketones) and carboxylations (to produce carboxylic acids). All these types of alkane reactions are promising toward the eventual exploration of alkanes as unconventional starting materials for synthesis. 

You are trying to make a methane complex L M(t -H—CH3)+ (8.17), by protonation of a methyl complex L MMe with an acid HA. Identify three things that might go wrong and suggest ways to guard against each. 

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