1,4,7-Triazacyclononane, 1,4,7-trimethyl

One of the first electrochemically characterized models was the diiron(II) cation [Fe2(0H)(02CCH3)2(Me3TACN)2]+, (Me3TACN = 1,4,7-trimethyl-1,4,7-triazacyclononane), the molecular structure of which is illustrated in Figure 28.35 In contrast to deoxyhaemerythin, both the two Fe(II) centres are hexacoordinate. 

Cohydrolysis of MnLCls (L= 1,4,7-triazacyclononane) and RuL Cl3 H20 (L = 1,4,7-trimethyl-1,4,7-triazacyclononane) in equimolar amounts in methanol containing an excess of sodium acetate gives rise to the asymmetric heterodinuclear species [L Ru(/i-0)(/u-CH3C00)2MnL]PFg on addition of sodium hexafluorophosphate. A model to interpret the strong spin-exchange coupling in this complex was presented." ... 

There have also been several examples of valence-delocalized Fe(II)Fe(III), S = 9/2 species generated from diiron complexes supported by terminally chelating ligands [(Me3-tacn)2Fe2(/u.-OH)3] + (Me3-tacn= 1,4,7-trimethyl-1,4,7-triazacyclononane), and [(C24H26N402)Fe2(M-OAc)2] +. ... 

Dimeric complexes of the V02 group have single 0x0-bridges giving a [O2V-O-VO2] core such as in [L2V204(/x-O)] (L = 1,4,7-trimethyl-1,4,7-triazacyclononane), or a rare type of dioxo bridge as seen in the compound shown in (10). In this compound, the p-O distances are asymmetric, as indicated, the shorter being about 1.675 A and the other around 2.27 A. 

The first [M Dm3(ttnFe)2](C104)2 complexes of this type were obtained [79] by the interaction of iron(II) acetate and copper, zinc, nickel, cobalt, and manganese acetates with dimethylglyoxime and 1,4,7-trimethyl-1,4,7-triazacyclononane ttn) in methanol in the presence of triethylamine (Reaction 20). In this case, a triazamacrocycle served as the protecting group in the octahedral capping nFe "03 fragment. 

Brij BSA Bu CBDTS CD CHIRAPHOS Cn COD Cp Cp CTAB DBA = seep.78 = bovine serum albumin = butyl = tetrasulfonated cyclobutane-DIOP, 37, see p. 17 = cyclodextrin = 2,3-bis(diphenylphosphino)butane = 1,4,7-trimethyl-1,4,7-triazacyclononane = 1,5-cyclooctadiene = r 5-cyclopentadienyl = ti5-CsMe5, r 5-pentamethylcyclopentadienyl = hexadecyltrimethylammonium bromide = 1,5-diphenyl-l, 4,-pentadiene-3-one (dibenzylideneacetone)... 

LLCT = ligand-to-ligand charge-transfer LMCT = ligand-to-metal charge-transfer LUMO = lowest-unoccupied molecular orbital MC = metal-centered MeaTACN = 1,4,7-trimethyl-1,4,7-triazacyclononane MePa = l,l,l-tris(diphe-nylphosphinomethylethane) Mes = mesityl MLCT =... 

Rhodium-catalyzed polymerization of ethylene was reported very early in the history of organometallic chemistry, but the more recent hard-ligand triaza-cyclononane complexes of rhodium (Cn = 1,4,7-trimethyl-1,4,7-triazacyclononane) are the best characterized. At room temperature, ethylene is slowly polymerized by [(Cn)RhMe(H20)(OH)]+ in water and more rapidly in acetone. At 50 °C, the disappearance of the methyl resonance in the presence of ethylene is first order in ethylene and in rhodium. The polymerization rate profile versus pH in water indicates that [CnRhMe(OH2)(OH)]+ is the most effective catalyst, [CnRhMe(OH2)2] is much slower, and... 

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