Inorganic Chemistry Communications (v.3, #1)

Low hapticity intermediates in the carbonylation of (η 5-2,6-dimethyl-5-hydro-s-indacenide)-Ir(η 4-COD) by Alfonso Venzo; Annalisa Bisello; Alberto Ceccon; Francesco Manoli; Saverio Santi (1-4).
The isomeric (η 1-5-hydro-2,6-dimethyl-s-indacenide)-Ir(η 4-COD)(CO)2 and (η 1-7-hydro-2,6-dimethyl-s-indacenide)-Ir(η 4-COD)(CO)2) complexes are produced in a 1/1 ratio in the first step of the carbonylation reaction of (η 5-2,6-dimethyl-5-hydro-s-indacenide)-Ir(η 4-COD) at 233 K. At 243 K, in the presence of excess CO, they slowly convert into the isomeric (η 1-5-hydro-2,6-dimethyl-s-indacenide)-Ir[η 2-COD)(CO)3) and (η 1-7-hydro-2,6-dimethyl-s-indacenide]-Ir(η 2-COD)(CO)3. The unprecedented η 2-coordination of COD towards iridium has been detected both by conventional variable temperature 1D 1H NMR spectroscopy and by a single-temperature 2D EXSY experiment.
Keywords: Iridium complexes; Hydroindacenide complexes; η1-Metal complexes; η2-COD; 2D-EXSY spectroscopy;

Complex formation between molybdenum and tantalum alkoxides has been achieved via activation of the homometallic species, both being Lewis acids, by either partial hydrolysis or partial thermolysis in hydrocarbon media. The crystal structures of the products formed, Mo2Ta4O8(OMe)16 (I) and Mo4Ta2O8(OiPr)14 (II) respectively, are described.
Keywords: Crystal structures; Molybdenum complexes; Tantalum complexes; Alkoxide complexes;

Synthesis and structural characterization of [RuCl2(CO)2(TePh2)2]·1/2C6H6 by Raija Oilunkaniemi; Risto S Laitinen; Markku Ahlgrén (8-10).
The reaction of Ph2Te with [RuCl2(CO)3]2 affords a monomeric ruthenium complex [RuCl2(CO)2(TePh2)2]. The X-ray structure shows the formation of the trans(Ph2Te), cis(Cl), cis(CO) isomer. The 13C NMR and 125Te NMR spectra of the complex are reported.
Keywords: Ruthenium complexes; Tellurium complexes; Carbonyl complexes; Crystal structures; NMR spectroscopy;

[Ir(CO)2I3Me] reacts with carboxylic acids or hydrogen (but not with mineral acids) at elevated temperature to cleave the iridium(III)–methyl bond liberating methane; a cyclic transition state is proposed for the reactions with RCOOH.
Keywords: Methyl complexes; Iridium complexes; Bond cleavage; Catalytic carbonylation; Methane;

Addition of lithium hexamethyldisilazide to calcium or barium bis(hexamethyldisilazide) in THF resulted in the synthesis of two unique but very different mixed-metal complexes: X-ray crystallography shows these to be, respectively, the heterobimetallic complex [Ca{N(SiMe3)2}3Li(THF)] (1), containing two calcium–lithium bridging amide ligands and the remarkable co-crystalline compound [Ba{N(SiMe3)2}2(THF)3][Li2{N(SiMe3)2}2(THF)2] (2).
Keywords: Lithium complexes; Group 2 metal complexes; Crystal structures; Mixed-metal complexes; Amide ligands;

The reaction of trans-[PtCl2(NCMe)2] with a 5-fold excess of MeNH2 in CH2Cl2 at −10°C affords in high yield the bis-amidine complex trans-[PtCl2{Z-N(H)C(NHMe)Me}2] (1), where both the amidine ligands assume the Z configuration corresponding to the trans addition of the amine along the CN triple bond. Compound 1 has been fully characterized by spectroscopic techniques and also by X-ray diffraction analysis.
Keywords: Platinum complexes; Nitrile complexes; Amidine complexes; Crystal structures;

Theoretical studies have shown that the low basicity of the phosphite ligand P(O-o-tBuPh)3 in the Rh(0) complex (CO)2(P(O-o-tBuPh)3)Rh-Rh(P(O-o-tBuPh)3)(CO)3 favours the non-bridged structure over the bridged one, but is not responsible for the absence of the expected sixth carbonyl in the structure. The steric effects of the bulky ligand play an important role in the unusual stability of the asymmetric complex.
Keywords: Rhodium complexes; Phosphite ligand; Electronic effects; Steric effects; DFT; Molecular mechanics;

A coordination polymer derived from the copper(II) complex of a bis-(salicylhydrazone) derived from iminodiacetic acid diethyl ester by Harry Adams; David E Fenton* ; Giovannina Minardi; Emanuela Mura; Angelo M Pistuddi; Costantino Solinas* (24-28).
A coordination polymer bearing alternate mononuclear and phenoxy-bridged dinuclear copper(II) motifs has been synthesised from a bis-(salicylhydrazone) derived from the diethyl ester of iminodiacetic acid. The structure of the polymer has been established by X-ray crystallography.
Keywords: Crystal structures; Copper(II) complexes; Coordination polymers;

The first examples of ferrocene derived cyclocarbaphosphazenes have been synthesized by the reaction of Fe(η-C5H5)-[η-C5H4CH2P(S)(CH2OLi)2] with (RR′NCN)2(Cl2PN) [RR′N=Me2N and PhCH2(Me)N]. The crystal structure of the spirocyclic compound {Fe(η-C5H5)-[η-C5H4CH2P(S)(CH2O)2PN)]}(Me2NCN)2 has been determined and shows an axial orientation of the ferrocenylmethyl group with respect to the six-membered chair form of the spirocycle.
Keywords: Hydroxymethylferrocenes; Phosphine sulfide; Cyclocarbaphosphazene; Spirocycle;

Synthesis, antiapoptotic biological activity and structure of an oxo–vanadium(IV) complex with an OOO ligand donor set by Diego del Rı́o; Agustı́n Galindo; Juan Tejedo; Francisco J Bedoya; Andrea Ienco; Carlo Mealli (32-34).
The oxo–vanadium(IV) complex VO(oda)(H2O)2 (1) (oda=oxydiacetate, O(CH2COO)2) was obtained by reaction of aerobic aqueous solutions of VO(acac)2 with oxydiacetic acid, O(CH2COOH)2. The antiapoptotic biological activity of 1 was studied in insulin-producing cells. Chemically generated nitric oxide (NO) triggers apoptotic events, such as the appearance of oligonucleosomes in cytosol, and this response was prevented by the presence of 1 in the culture medium. The molecular structure of 1 has been determined by X-ray diffraction analysis.
Keywords: Vanadium complexes; Oxo complexes; Oxydiacetate complexes; Apoptosis; Crystal structures;

A novel dinuclear ruthenium complex, [(tpy)Ru(tmbimbpyH4)Ru(tpy)](ClO4)4, has been synthesized to introduce a new proton-induced molecular switching system, where tpy=2,2′:6′,2″-terpyridine and tmbimbpyH4=2,6,2′,6′-tetra(4,5-dimethylbenzimidazol-2-yl)-4,4′-bipyridine. Both fully protonated and deprotonated forms of the dinuclear Ru complex were isolated and the forms were interchangeable by the addition of acid or base. A longer wavelength shift and a negative oxidation potential shift were observed when the protonated Ru complex was fully deprotonated.
Keywords: Dinuclear Ru complex; Bis tridentate ligand; Protonation/deprotonation; Benzimidazole derivative;

Relativistic ab initio molecular orbital calculations have been performed on the monoligated neutral complex [PtSiH2] in order to investigate the nature and energetics of the interaction between the metal and SiH2 ligand. The results suggest that the silylene ligand acts as both a σ-donor and π-acceptor but is a relatively better π-acceptor. The electronic structure of [PtSiH2] is analyzed in detail as measured by Wiberg’s bond indices, charge distributions and orbital populations.
Keywords: Platinum; Sylylene; Electronic structures; Bonding;

A new synthetic procedure for the efficient preparation of dinuclear ruthenium(II) polypyridyl complexes is reported. The compounds synthesised are [(bpy)2Ru(BPBT)Ru(bpy)2](PF6)2 and [(bpy)2Ru(BPZBT)Ru(bpy)2](PF6)2 (bpy=2,2′-bipyridine; H2BPBT=5,5′-bis(pyridin-2-yl)-3,3′-bis(1,2,4-triazole); H2BPZBT=5,5′-bis(pyrazin-2-yl)-3,3′-bis(1,2,4-triazole). Electrochemical experiments show that the two dinuclear systems investigated exhibit pH switchable intercomponent interactions.
Keywords: Ruthenium complexes; Coupling reactions; Electrochemistry; Dinuclear complexes;

A fluorescent chemosensor based on a ruthenium(II)-terpyridine core containing peripheral amino groups that selectively sense ATP in an aqueous environment by Miguel E Padilla-Tosta; José Manuel Lloris; Ramón Martı́nez-Máñez; Teresa Pardo; Juan Soto; Angel Benito; Maria Dolores Marcos (45-48).
The selective sensing of the ATP anion in an aqueous environment over phosphate, sulfate, and chloride using a fluorescence chemosensor based on Ru(tpy)22+ cores attached to polyammonium groups is reported.
Keywords: Ruthenium complexes; ATP sensing; Fluorescent chemosensor;