Trans-effects in octahedral transition metal complexes

New features in the redox coordination chemistry of metal nitrosyls {M-NO+ ; M-NO•; M-NO- (HNO)}

Nitrosyl complexes of ruthenium

Two new pentadentate, pendent arm macrocyclic ligands of the type 1-alkyl-4,7-bis(4-tert-butyl-2-mercaptobenzyl)-1,4,7-triazacyclononane where alkyl represents an isopropyl, (LPr)2-, or an ethyl group, (LEt)2-, have been synthesized. It is shown that they bind strongly to ferric ions generating six-coordinate species of the type [Fe(Lalk)X]. The ground state of these complexes is governed by the nature of the sixth ligand, X:  [FeIII(LEt)Cl] (2) possesses an S = 5/2 ground state as do [FeIII(LEt)(OCH3)] (3) and [FeIII(LPr)(OCH3)] (4). In contrast, the cyano complexes [FeIII(LEt)(CN)] (5) and [FeIII(LPr)(CN)] (6) are low spin ferric species (S = 1/2). The octahedral {FeNO}7 nitrosyl complex [Fe(LPr)(NO)] (7) displays spin equilibrium behavior S = 1/2 ⇌ S = 3/2 in the solid state. Complexes [Zn(LPr)] (1), 4·CH3OH, 5·0.5toluene·CH2Cl2, and 7·2.5CH2Cl2 have been structurally characterized by low-temperature (100 K) X-ray crystallography. All iron complexes have been carefully studied by zero- and applied-fiel...

Tuning the Electronic Structure of Octahedral Iron Complexes [FeL(X)] (L = 1-Alkyl-4,7-bis(4-tert-butyl-2-mercaptobenzyl)-1,4,7-triazacyclononane, X = Cl, CH3O, CN, NO). The S = 1/2 ⇌ S = 3/2 Spin Equilibrium of [FeLPr(NO)]

Publisher Summary This chapter discusses the binding and activation of carbon monoxide, carbon dioxide, and nitric oxide by transition-metal complexes and examines the selected reactions of these molecules, which are catalyzed by metal complexes in solution. These three simple oxides exhibit significantly different coordination chemistries and diverse reactivity patterns when bonded to transition-metal ions. The activation of each, thus poses different problems in the field of homogeneous catalysis. By considering these three simple inorganic oxides together, the chapter compares the similarities and differences apart from examining each independently. Homogeneously catalyzed reactions can be viewed as occurring in a sequence of steps, each of which involves a change in one or more of the following properties of the catalyst metal complex: coordination number, metal-ion oxidation state, and valence-electron count. Of these properties, the metal ion oxidation state seems most susceptible to confusion, especially with ligands, such as nitrosyl, π-bonded allyl, and bridging hydride.

The Binding and Activation of Carbon Monoxide, Carbon Dioxide, and Nitric Oxide and Their Homogeneously Catalyzed Reactions

The biological role of molybdenum, biophysical studies of the molybdenum atoms in molybdo-enzymes, and aspects of coordination chemistry that bear on the understanding of molybdo-enzymes.

Some aspects of the bioinorganic chemistry of molybdenum

Stereochemical control of valence. 5. Comparison of the molecular and electronic structures of five- and six-coordinate o-phenylenebis(dimethylarsine) complexes of the {FeNO}7 group

Structural chemistry of the (cono)8 (cobalt mononitrosyl) group. structure of trans-perchloratonitrosylbis(ethylenediamine)cobalt perchlorate, (co(no)(c2n2h8)2(oclo3))(clo4)

Kathleen Bizot Swedo

Papers

Some aspects of the bioinorganic chemistry of molybdenum

Stereochemical control of valence. 5. Comparison of the molecular and electronic structures of five- and six-coordinate o-phenylenebis(dimethylarsine) complexes of the {FeNO}7 group

Structural chemistry of the (cono)8 (cobalt mononitrosyl) group. structure of trans-perchloratonitrosylbis(ethylenediamine)cobalt perchlorate, (co(no)(c2n2h8)2(oclo3))(clo4)

Stereochemical control of valence. 5. Comparison of the molecular and electronic structures of five- and six-coordinate o-phenylenebis(dimethylarsine) complexes of the {FeNO}7 group