Inorganic Chemistry Communications (v.4, #5)

Contents (iii-iv).

Coordination complexes of β-thioether appended tetraazaporphyrin by Rajendra Prasad; Anil Kumar; Elisa Murguly; Neil Branda (219-222).
2,3,7,8,12,13,17,18-Octakis(benzylthio)tetraazaporphyrin magnesium(II) [Mg(TAP-S8Bz8)] was synthesized. Exploiting the coordination tendency of the thioether substituents Cp(PPh3)RuII and (Phen)2RuII fragments were bonded to the Mg(TAP) core to get molecular dyads. Spectral and electrochemical characteristics of the dyads as well as of the parent complex have been investigated.
Keywords: Azaporphyrin; Cyclopentadienyl; Phenanthroline; Ruthenium(II);

Synthesis of supramolecular-templated mesostructured tin oxide by Yu-De Wang; Chun-Lai Ma; Xiao-Dan Sun; Heng-De Li (223-226).
In this study mesostructured tin oxide was synthesized for the first time under acidic conditions at room temperature. Mesostructured tin oxides possessing different d-spacing were synthesized using a cationic surfactant (cetyltrimethylammonium bromide, CTAB) as the organic supramolecular template, hydrous tin chloride (SnCl4·5H2O) as the inorganic precursor and NH4OH as the counterion source. The synthetic factors (such as the ratio of reactants, aging time) were investigated. The resultant products were examined by XRD, TEM, and TGA. It was found that the ratio of CTAB/Sn4+ was important to the d-spacing of the (1 0 0) layer of the material. The formation of the tin oxide mesostructured material was proposed to be due to the presence of interactions between the supramolecular template and inorganic precursors Sn4+ and OH, which was supposed to self-assemble around the cationic surfactant molecules.
Keywords: Supramolecular template; Inorganic precursor; Mesostructured tin oxide; Aging time;

The anodic oxidation of rhenium metal in isopropanol at temperatures not exceeding 20°C provides with good yields the crystalline Re4O6(OiPr)10 (I) complex, the molecular structure of which is built up around a practically ideal (Re–Re 2.52–2.54 Å) planar rhombus of metal atoms, being thus connected by five equivalent metal–metal bonds in a system with only six cluster electrons.
Keywords: Rhenium alkoxide; Electrochemical synthesis; X-ray structure; Metal–metal bonds; Cluster compounds;

A simple and efficient pH-induced molecular “on/off” switching has been devised based on a symmetric bridged ruthenium dimer, [(edta)Ru(μ-Lb)Ru(edta)] n (where n=4 or 3; Lb=benzotriazolate or 2H-benzotriazole; edta=ethylenediaminetetraacetate), by exploiting its unusual mixed-valence state behavior as a function of the pH. The intervalence transfer (IT) related phenomena have been rationalized in the light of the Mulliken–Hush formalism. Depending on the proton concentration, the electronic coupling and delocalization can be modulated to induce class III (deprotonated bridging ligand), class II (protonated), or even an intermediate borderline class II/class III system features.
Keywords: Ruthenium-edta; Benzotriazole; Proton-coupled electron transfer; Mixed-valence; Intervalence; Molecular devices;

Synthesis, characterization and single crystal X-ray structure of cis-dichloro-bis-2-(2-pyridyl)-4-(methylcarboxy)quinoline ruthenium (II), a versatile polypyridyl ruthenium (II) building precursor with additional two peripherally functionalizable sites will be described.
Keywords: 2-(2-pyridyl)-4-(methylcarboxy)quinoline; Crystal structure; Ruthenium (II) complex;

Assembly of tris(2-aminoethyl)amines and its unusual conversion by silver(I) ions by Hao Zhang; Jiwen Cai; Xiao-Long Feng; Jian-Zhong Liu; Xiao-Yuan Li; Liang-Nian Ji (241-244).
The reaction of AgNO3 with tris(2-aminoethyl)amine (tren) affords an unusual achiral grid with desirable chiral channels [Ag(tren)]NO3 (1), and a species of single-stranded helical polymer, [Ag(baep)]NO3 •MeOH (2), baep=1,4-bis(2-aminoethyl)-piperazine, which indicates that the polyamine ligand tren is converted during the process of the reaction.
Keywords: Coordination polymers; Ethylene migration; Polyamine; Silver(I);

A new defective ring-shaped polyoxomolybdate Na 28[Mo VI 112 Mo V 28 O 427 H 14(H 2 O)56]·  ca. 300H 2 O was synthesized from an acidified aqueous solution of Na2MoO4·2H2O with Na2S2O3·5H2O or NH2NH2·2HCl acting as reducing reagents. Its giant tire-like anion, which is formally based on the reported {Mo154}-type ring with removal of seven {Mo2}2+ units at certain positions, is built up by fourteen {Mo8} units fused with fourteen {Mo1} units and seven {Mo2}2+ units.
Keywords: Giant polyoxomolybdate; Synthesis; Crystal structure; Nano-sized cavity;

New chiral complexes of optical schiff base ligand (KL) derived from d-Camphor-β-sulphonic acid and p-nitrophenylhydrazine with Ln=La3+, Pr3+, Nd3+, Sm3+, Eu3+, Gd3+,   Tb 3+ , Dy3+, Ho3+ and Er3+ of the type LnL3 have been prepared and their structure assigned on the basis of analytical, spectral (XPS, CD, IR and electronic spectra), molar conductance, magnetic moments and thermal analysis methods.
Keywords: Schiff base; Lanthanide(III); d-Camphor-β-sulphonic acid; p-nitrophenylhydrazine; XPS spectra;

Electronic spectra of solid pentakis(dimethylamido)tantalum(V) by Horst Kunkely; Arnd Vogler (252-253).
The electronic spectra of the complex TaV(NMe2)5 are characterized by amide  →  Ta(V) ligand-to-metal charge transfer (LMCT) transitions. In the reflectance and excitation spectrum the longest-wavelength LMCT band appears at λ max∼415 nm. The emission of Ta(NMe2)5 which originates from the lowest-energy LMCT triplet occurs at λ max=578 nm and decays with τ=0.9  μs at r.t.
Keywords: Electronic spectra; Luminescence; Tantalum complexes; Amido complexes;

Structure of a tetranuclear heterometallic Ag(I)–Pt(II) complex with a triazolopyrimidine derivative by Mohammad Abul Haj; Miguel Quirós; Juan M. Salas; René Faure (254-256).
The crystal structure of the tetranuclear heterometallic compound [Pt2Ag2(7tpO)4(bpm)2(H2O)2](NO3)2·2H2O is described, where bpm=bipyrimidine and 7tpO represents the anionic form of the ligand 4,7-dihydro-7-oxo-[1,2,4]-triazolo-[1,5-a]-pyrimidine. The complex cation in this compound includes two platinum and two silver atoms forming a –Ag–(7tpO)2–Pt–bpm–Ag–(7tpO)2–Pt–bpm– cyclic species. The bridging ligand 7tpO binds platinum and silver through the nitrogen atoms in positions 3 and 4, respectively, whereas each bipyrimidine moiety is also linked to a platinum and a silver atom, each atom being coordinated by the two nitrogen atoms of one ring of this ligand.
Keywords: Triazolopyrimidine; Tetranuclear complexes; Heterometallic complexes; Bipyrimidine; Platinum(II); Silver(I);

Structure of [2,6-bis(dimethylamino)methyl]phenyltin tribromide hydrate by Roman Jambor; Aleš Růžička; Jiřı́ Brus; Ivana Cı́sařová; Jaroslav Holeček (257-260).
The reaction of the 2,6-bis[(dimethylamino)methyl]phenyllithium with tin(IV) bromide affords, after recrystallisation from toluene on the air, the organotin(IV) compound [SnBr3{2,6-(Me2NCH2)2C6H3}(H2O)], 3, in which the N,C,N-ligand is bounded to Sn atom through the aryl carbon atom and one of the NMe2 groups only, while the second NMe2 group is protonated by hydrogen from the water molecule. The crystal structure analysis has shown dimeric structure of this compound, with unusually Sn–O–H–Br hydrogen bridges. This compound was characterised by NMR spectroscopy in solution and in the solid state and X-ray structure analysis.
Keywords: Organotin(IV); N-ligand; Hydrogen bonds; X-ray diffraction; NMR-spectroscopy;

Re(V) thiosalicylate complexes. Crystal structure of (Ph4As)[ReO(SC6H4CO2)2py]·H2O by Maxim Sokolov; Natalia Fyodorova; Natalie Pervukhina; Vladimir Fedorov (261-263).
The Re(V) thiosalicylate complex [ReO(SC6H4CO2)2py] was prepared from [ReO2(py)4]Cl and thiosalicylic acid and isolated as Ph4As+ (1) and Ph4P+ (2) salts. The structure of 1 was determined by X-ray crystallography.
Keywords: Rhenium complexes; Thiosalicylic acid; Crystal structures;

The title complex was prepared by the reaction of N,N -bis(3-aminopropyl)ethylenediamine (3,2,3-tet) and NaClO4 in the presence of copper(II) ion. The complex forms a coordination polymer bridged with μ-bidentate perchlorato ligand. The geometry around copper(II) ion is tetragonally distorted octahedron by the coordination of four nitrogens of 3,2,3-tet with square-planar arrangement and two perchlorato ligands in apical sites. An water molecule of the unit complex is located between [Cu(3,2,3-tet)] 2+ and uncoordinated perchlorate with hydrogen bonds.
Keywords: Copper(II) complex; N,N -bis(3-aminopropyl)ethylenediamine; Coordination polymer; μ-bidentate perchlorato ligand;

Silver(I) helicates with 2-(arylazo)pyrimidines. Single crystal X-ray structure of {2-(phenylazo)pyrimidine}silver(I) nitrate by Prasanta Kumar Santra; Umasankar Ray; Satyanarayan Pal; Chittaranjan Sinha (269-273).
2-(Arylazo)pyrimidines (aapm) react with AgNO3 in methanol and crystallises in a single strand right-handed helical coordination polymer, [Ag(aapm)(NO3)] n . The X-ray structure determination of Ag[2-(phenylazo)pyrimidine] (papm) (NO3) (abbreviated, Ag(papm)(NO3)) suggests the triangular coordination around Ag(I) which is made up of chelated azoimine, –NN–CN–, function from one ligand and the third donor centre is coming from meta-related pyrimidine-N of the adjacent papm of the second Ag(papm)-unit. The coordination polymer is propagated through pyrimidine-N→Ag bonding.
Keywords: Silver(I) complexes; Arylazopyrimidines; Coordination polymer; X-ray crystal structure;