Inorganic Chemistry Communications (v.4, #2)

Intercalation of organic dyes in the layered host lattice V2O5 by Tsuneo Kuwahara; Hideyuki Tagaya; Jun-ichi Kadokawa (63-65).
New methyl yellow/V2O5 intercalation compounds were prepared through the exfoliation/restacking method. Though Li-intercalated V2O5 had no clear order structure, the methyl-yellow-intercalated V2O5 had a layered structure, and interlayer spacing increased to 1.38 nm from 0.44 nm for V2O5.
Keywords: Exfoliation; Intercalation; Methyl yellow; Restacking; Vanadium pentoxide;

Condensation of pyridine-2-carbonitrile (2-CNpy) with 2-aminoethanol (L1) or 1-amino-2-propanol (L2) in ethanolic solutions of CuX 2  (X=Cl or Br) proceeds readily under mild reaction conditions to form stable solid complexes of composition [CuX 2(amL-NH)2]·nH 2 O  (n=0–2) which contain the imino form of N-2-hydroxyalkylpyridine-2-carboxamidines (amL-NH). The crystal structure of dibromo-bis(N-2-hydroxypropyl-pyridine-2-carboxamidine-N,N ) copper(II) and IR data confirm bidentate N,N-coordination of N-2-hydroxyalkylpyridine-2-carboxamidines (via the nitrogen atom of the pyridine ring as well as via the nitrogen atom of the terminal imino group). On the other hand, the complex of composition [CuCl2(amL1-NH2)] contains only a terdentate N,N,O-coordinated amino form of N-2-hydroxyethylpyridine-2-carboxamidine (amL1-NH2) molecules as organic ligands. Based on the molecular structure the electronic, IR and conductometric measurements are discussed.
Keywords: Copper(II) complexes; Nucleophilic reaction; Pyridine-2-carbonitrile; N-2-hydroxyalkylpyridine-2-carboxamidines; Crystal structure;

Structures of two 1-D coordination polymers, [MII(pyr)2(N(CN)2)2] (M=Mn (1), Co (2), pyr=2-pyrrolidone), have been determined. They are isomorphous and belong to monoclinic space group, Cm with Z=2. The magnetic properties of two compounds (2–300 K) show the existence of weak antiferromagnetic exchange interaction between paramagnetic centers along chains.
Keywords: 1-D; Structure; Magnetic property; Dicyanamide;

The two-dimensional hydrogen-bonded honeycomb networks formulated as (4,4-H2bipy)2[Ni(NCS)4(H2O)2](NO3)2(4,4-H2bipy=4,4-bipyridinium) with R 10 12(64) rings and ca. 24×20 Å internal dimensions are triply interwoven to generate two-dimensional `chicken-coop' sheets, featuring unusual hydrogen bonds involving the NO3 groups.
Keywords: Crystal engineering; Hydrogen bonds; Nickel thiocyanate; 4,4-Bipyridinium;

A novel coordination polymer, [Zn2(bpy)(NTA)Cl·H2O] n (bpy = 2,2-bipyridine, H3 NTA = nitrilotriacetic acid), has been synthesized and its structure determined by X-ray diffraction analysis, which consists of a ladder running along b axis where ZnII ions are linked through the carboxylic groups acting as the rungs and rails of the ladder.
Keywords: Ladder; Crystal structure; Zinc; Nitrilotriacetate (NTA);

Pronounced effects of counterions on intramolecular electron transfer in 1,1‴-dinaphthylmethylbiferrocenium cation by Teng-Yuan Dong; Tzon-Jyi Lee; Bor-Ruey Huang; Shie-Ming Peng; Gene-Hsiang Lee (82-85).
The X-ray structure of 1,1‴-dinaphthylmethylbiferrocenium BF4 has been determined. The 57Fe Mössbauer and EPR results of 1,1‴-dinaphthylmethylbiferrocenium BF4 and PF6 salts are also reported. The relatively minor perturbations caused by the counterions have pronounced effects on the rate of intramolecular electron transfer.
Keywords: Mixed-valence 1,1‴-dinaphthylmethylbiferrocenium; Biferrocenium; Metallocene; Electron transfer;

Electrospray mass-spectrometry (ESI-Mass) has revealed that some copper(II) compounds, but not others, catalyze oxygenation of amyloid β-peptide (1–40), undoubtedly at methionine sulfur atom, in the presence of hydrogen peroxide; this will give an important information to elucidate the role of copper ion in the brain to induce neurodegenerative disorders, such as Alzheimer's and Prion diseases.
Keywords: Amyloid beta-peptide; Copper(II)-peroxide adduct; Oxygenation reaction; Electrospray mass-spectrometry;

Complexation of macrocycles having two 1,3-diene units by iron carbonyls leads to a mixture of trans and cis macrocycles containing two (η 4-diene)Fe(CO)3 complexes. The structures of the macrocycles are unambiguously determined by X-ray analysis. In the trans diiron complex macrocycle, the planes of the two η 4-diene units are situated in the macrocyclic plane and the two Fe(CO)3 groups are located above and below the macrocyclic plane to each other. In the cis diiron complex macrocycle, however, one of the two η 4-diene planes is in the macrocyclic plane and the other is perpendicular to the macrocyclic plane. Both the trans and cis diiron complex macrocycles are conformationally flexible in solution.
Keywords: Macrocycle; (η 4-Diene)tricarbonyliron; Crystal structure; Conformational analysis;

The paramagnetic complex [W(η-C5Me5)Cl3(η 2-O2CC6H4NH2-2)] (1) has been obtained by reaction of [W(η-C5Me5)Cl4] with anthranilic acid [1,2-(NH2)(CO2H)C6H4]; the X-ray crystal structure shows a pseudo-octahedral geometry with a mer arrangement of chlorines and a symmetrically chelating carboxylate group containing a pendant non-coordinated NH2 group. Contrastingly, [ReCl(OEt)(PPh3)2(NC6H4CO2)] (2), the product of the reaction between [ReOCl3(PPh3)2] and anthranilic acid contains pseudo-octahedral rhenium with a chelating imidobenzoate ligand and trans-phosphines which are mutually cis to the bent imido function [Re–N(1)–C(1)=143.5(3)°]. The carboxylate group of the chelating ligand is trans to a chloride with the remaining site (trans to the imido function) occupied by an ethoxide ligand.
Keywords: Carboxylate; Imidobenzoate; X-ray crystallography; Tungsten; Rhenium;

The new triple-decker complexes [(μ,η 5:η 5-C4Me4P)( FeCp )( MCp )](BF4)2 ( 9 :M=Rh ; 10 :M=Ir ) are obtained from the phosphaferrocene Cp Fe(C 4 Me 4 P) (3a) by electrophilic stacking reactions in acetone. These stacking reactions are suppressed by the presence of even rather weak nucleophiles. In acetonitrile as solvent the σ-bonded complexes [ Cp Fe (μ,η 1:η 5-C4Me4P) M(NCMe)2 Cp ] CF3SO3 ( 11 :M=Rh ; 12 :M=Ir ) are obtained, and Cp Fe (μ,η 1:η 5-C4Me4P) Rh(O 3 SCF 3)2 Cp (14a) is formed when triflate ions are present in acetone. Nucleophilic degradation of 9 and 10 in acetone produces the corresponding sandwich complexes [ Cp Rh (C4Me4P)]BF4 (15) (inter alia), and [ Cp Ir (C4Me4P)]BF4 (16).
Keywords: Phospholyl; Phosphacyclopentadienyl; Sandwich complexes; Triple-decker complexes; Ligand transfer reactions;

The first dimeric half-sandwich gadolinacarborane of the “carbons apart” C2B4-carborane ligand system by Narayan S Hosmane; Shoujian Li; Chong Zheng; John A Maguire (104-107).
The reaction between the THF solvated “carbons apart” dinatracarborane, closo-exo-4,5-Na(THF)2–1-Na(THF)2–2,4-(SiMe3)2C2B4H4 (1), and anhydrous GdCl3 in a 1:1 molar ratio in dry benzene at 0°C, followed by extraction and crystallization of the product from an anhydrous n-hexane/TMEDA/THF solution mixture resulted in the isolation of off-white crystals of the dimeric half-sandwich dichlorogadolinacarborane, {1,1-Cl2[μ,μ -Na(TMEDA)]–1-(THF)-2,4-(SiMe3)2closo-η 5-1-Gd-2,4-C2B4H4}2 (2) in 88% yield.
Keywords: Carborane; Gadolinacarborane; Half-sandwich complex and metallacarborane;

Bisdiolatotungsten(VI) complexes of the type [W(diol)2(phe)2] and [W(diol)2(biphe)] (diol =aliphatic diolate dianion, phe = substituted phenolate, biphe = substituted biphenolate) were studied as catalyst precursors for ring opening metathesis polymerization of norbornene and dicyclopentadiene. These compounds form active catalysts when activated by Et2AlCl. Syntheses of two new precursor complexes, [W(eg)2(t Bu 2 phe)2] and [W(eg)2(t Bu 4 biphe)] along with the crystal structure of latter are also described.
Keywords: Alkoxide complexes; Phenolate ligands; Tungsten; Catalysis;

The reaction of the Mn2+ (aq) and [Cr(bipy)(C2O4)2] (aq) ions with 4,4-bipyridine-N,N -dioxide leads to a heteropolymetallic system, [Mn(4,4-bipyridine-N,N -dioxide) (H2O)4][Cr(bipy)(C2O4)2]2·8H2O (1). The crystal structure of 1 consists of one-dimensional chains, ∞ 1[Mn(4,4-bipyridine-N,N -dioxide) (H2O)4] n 2n+, with Mn(II) ions bridged by 4,4-bipyridine-N,N -dioxide ligands. The infinite homometallic chains are interconnected through hydrogen bonds with the water molecules and the [Cr(bipy)(C2O4)2] anions. The cryomagnetic measurements of compound 1 reveal weak anti-ferromagnetic interactions between the manganese(II) ions within the chain (J=−1.2  cm −1 ).
Keywords: Crystal structure; Manganese complexes; Chromium complexes; 4,4-bipyridine-N,N -dioxide complexes; Magnetic properties;