Inorganic Chemistry Communications (v.5, #9)

Contesnts List (iii-iv).

A new cucurbituril-based metallo-rotaxane by Xuyang He; Gang Li; Huilan Chen (633-636).
A new metallo-rotaxane was formed in the aqueous solution through the self-assembly of psuedo-rotaxane of cucurbituril/spermine and alkylcobaloxime. And it was characterized by 1HNMR, ESI-MS, and UV/Vis analysis.
Keywords: Metallo-rotaxane; Cucurbituril; Alkylcobaloxime; Self-assembly;

The syntheses, structures and luminescent properties of two unusual mixed-metal coordination polymers, namely [Ag4Cd2(tren)2(CN)7.5][Ag(CN)1.5] 1 and [Au2Cd(tren)(CN)4]·H2O 2 (tren = tris(2-aminoethyl)amine), are presented. Both compounds contain abnormal metal cords of oligocyanometallic anions as building blocks wherein the d10–d10 interaction plays a crucial role in the metal–metal assembly.
Keywords: Coordination polymers; Luminescent emission; Coinage metal; Cyano;

Syntheses, structures, and luminescence properties of a new family of three-dimensional open-framework lanthanide coordination polymers by Zheng Wang; Chuan-Ming Jin; Ting Shao; Yi-Zhi Li; Kou-Lin Zhang; Hong-Tao Zhang; Xiao-Zeng You (642-648).
Deprotonation of 2,6-naphthalenedicarboxylic acid (H2NDC) with pyridine followed by its copolymerization with Ln(III) nitrates (where Ln = Eu, Tb, Ce) in DMF at room temperature gave a family of 3-D open-framework lanthanide coordination polymers, formulated as {[Ln2(NDC)3(DMF)4mH2O}n (where Ln = Eu, Tb, Ce, 13; m=3, 4, 2 for 13, respectively, DMF =  N,N -dimethylformamide, and H2NDC = 2,6-naphthalenedicarboxylic acid) on the basis of elemental analysis and single-crystal X-ray diffraction. Compounds 13 were isostructural and crystallized in triclinic space group P(-1). In these structures, lanthanide ion dimers were interlinked together by NDC ligands with three different carboxylate coordination modes, to yield scaffolds with 3-D interconnecting tunnels where enclathrated water molecules reside. The results of IR and TG were consistent with the structural determination results. Fluorescence measurements show that 1 and 2 emit strong red and green light, respectively, upon irradiation with UV–vis light source. However, these open frameworks collapsed upon desolvation as evidenced by XRPD investigations, which renders their potential use as fluorescent sensors impossible.
Keywords: Coordination polymers; Lanthanides; Open framework; Fluorescent sensor;

1,2-Di-(o-salicylaldiminophenylthio)ethane reacts with Co(II) salts to form a complex with oxidative cleavage of the C–S bond, to result in the formation of a Co(III) complex of the cleaved ligands.
Keywords: 1,2-Di-(o-salicylaldiminophenylthio)ethane; Oxidative cleavage of C–S bond; Crystal structure of Co(III) complex; Activation by Co(II) salts;

Bimetallic platinum complexes containing linear tetraphosphine ligands by Padma Nair; Gordon K. Anderson; Nigam P. Rath (653-656).
The meso and rac forms of the tetraphosphine ligand bis[(diphenylphosphinoethyl)phenylphosphino]methane, Ph2PCH2CH2PPhCH2PPhCH2CH2PPh2 (DPPEPM), have been separated and found to react with 2 equiv of [PtCl2(cod)] or [PtMe2(cod)] to generate bimetallic complexes of the form [Pt2X4(μ-DPPEPM)]. When [PtClMe(cod)] is treated with the tetraphosphine followed by TlPF6, the chloride-bridged species [Pt2Me2(μ-Cl)(μ-DPPEPM)]PF6 is obtained. The solid state structures of [Pt2X4(μ-meso-DPPEPM)] (X=Cl, Me) are reported, along with preliminary studies of some hydrogenation reactions catalyzed by the bimetallic derivatives.
Keywords: Tetraphosphine; Platinum complexes; Crystal structure(s); Hydrogenation reactions;

Thermal quenching of 2E in Cr(bpy)3 3+ (bpy = 2,2-bipyridine) solutions where back-intersystem crossing is not important is compared with the quenching of Cr(NCS)6 3− and trans-Cr(NH3)2(NCS)4 in several solvents. Solvent motion enhances excited state relaxation whether or not back-intersystem crossing is a significant relaxation pathway. The relationship between motionally induced decay and the exponential or nonexponential character of the decay is discussed.

Bimetallic octacyanometallates [Mo(CN)8Ni2(pn)4] n ·4nH2O (1) and [Mo(CN)8Ni(en)2(H2O)][Ni(en)3]·2H2O (2) based on [Mo(CN)8]4− were synthesized in aqueous solution, and their crystal and molecular structures have been determined. The complex [Mo(CN)8Ni2(pn)4] n ·4nH2O (1) consists of novel two-dimensional honeycomb-like layers. The complex [Mo(CN)8Ni(en)2(H2O)][Ni(en)3]·2H2O (2) contains a binuclear anion [Mo(CN)8Ni(en)2(H2O)]2−,[Ni(en)3]2+ cation and two lattice water molecules. Magnetic studies suggest a possible weak antiferromagnetic interaction between Ni2+ ions in 1.
Keywords: Octacyanometallate; Honeycomb-like; Crystal structure; Magnetism;

Two novel β-octamolybdate supported rare earth metal complexes, [NH4]2[{Gd(DMF)7(β-Mo8O26)}][β-Mo8O26] 1 and [NH4][La(DMF)7(β-Mo8O26)] 2, were obtained from the reaction of (NH4)6Mo7O24·4H2O with LnCl3 (Ln=Gd for 1 and La for 2) at low pH values in the mixed solvents of H2O/DMF or H2O/DMF/CH3CN. The single X-ray diffraction studies reveal that 1 consists of discrete centrosymmetric heterometallic decanuclear [{Gd(DMF)7}2-β-Mo8O26]2+, [β-Mo8O26]4− and two amino cations. In each decanuclear [{Gd(DMF)7}2-β-Mo8O26]2+ cation, the β-octamolybdate moiety is linked to two eight-coordinated GdIII cations, which is coordinated by seven DMF ligands and one terminal oxygen atom of molybdenum center. Compound 2 is built up from DMF coordinated LaIII fragment and β-octamolybdate unit joined together through two terminal oxygen atoms of two molybdenum atoms. Ferromagnetic behavior is observed for 1 from the magnetic measurement, which might result from the exchange interaction through the bridging β-[Mo8O26]4− ligand or the presence of zero-field splitting.Two new β-octamolybdate supported rare earth metal complexes: [NH4]2[{Gd(DMF)7}2(β-Mo8O26)][β-Mo8O26] and [NH4][La(DMF)7 (β-Mo8O26)]
Keywords: Octamolybdate; Lanthanide; Heterometallic complexes; Magnetic susceptibility;

Self-assembly of dinuclear M2Cl4(C13H9N3)2: stepwise supramolecular array by π–π stacking by Changxing Shao; Wen-Hua Sun; Yong Chen; Ruji Wang; Chanjuan Xi (667-670).
The title compound aggregates to a parallel supramolecular architecture through the intermolecular π–π stacking and subsequently forms an infinite array in crystal. The magnetochemistry properties, UV spectra and oxidation potential of the two metal complexes were investigated.
Keywords: 2-(Pyrid-2-yl)quinoxaline; Coordination polymer; Three-dimensional structure; π–π interaction;

Micelle-template inducing synthesis of winding ZnS nanowires by Qingsheng Wu; Nengwu Zheng; Yaping Ding; Yadong Li (671-673).
Semiconductor single-crystal ZnS nanowires with diameters 40–80 nm and lengths up to tens of micron, which can bend and wind, have been synthesis by the reaction of Zn2+ with S2− in reverse micelle for the inducing template. The formation mechanism of ZnS nanowires has been studied. The results indicated that the formation of ZnS nanowires probably was via the process of the directional aggregation and orientated growth of the ZnS nanoparticles.
Keywords: Zinc sulfide; Nanowires; Template synthesis; Reverse micelle;

With regard to its electronic structure, the cation Icoll2 + (coll = collidine or 2,4,6-trimethylpyridine) is viewed as a coordination compound of iodine(I) with a p4 electron configuration. The lowest-energy excited state of Icoll2 + is suggested to be a ππ* collidine intraligand (IL) triplet which appears in absorption (λ max=332 nm, ε=250) and emission (λ max=405 nm, φ=0.001, τ∼90 ns). Owing to the heavy-atom effect of iodine this phosphorescence occurs at r.t. The longest-wavelength pp absorption is apparently obscured by the intense spin-allowed IL band at λ max=268 nm.
Keywords: Electronic spectra; Luminescence; Iodine compounds;

Triboluminescent phenomena of 2-hydroxyethylammonium tetrakis (dibenzoylmethide)europate (1) and pyrrolidonium tetrakis(dibenzoylmethide)europate (2) were firstly observed, and the crystal structure of dimethylbenzylammonium tetrakis(dibenzoylmethide)europate (3) was successfully determined after more than 35 years later. Crystal data for 3: orthorhombic, space group Pca21 (No.29), a=25.697(2), b=9.462(3), c=15.023(3) Å, Z=4. The Eu atom exhibits an eight-coordinate tetragonal antiprismatic geometry with an average Eu–O bond distance of 2.42(2) Å. Triboluminescent spectra of 13 are basically similar to that of their fluorescent spectra, and the observed triboluminescent emission correlates well with their acentric space group.
Keywords: Triboluminescence; Europate; Dibenzoylmethane;

A novel heterobimetallic W–Ge compound. X-ray crystal structure of [W(μ-Cl)(GeCl3)(CO)34-C7H8)] by Teresa Szymańska-Buzar; Tadeusz Głowiak; Izabela Czeluśniak; Marcin Górski (682-684).
The new heterobimetallic complex [W(μ-Cl)(GeCl3)(CO)34-C7H8)] (1) has been prepared by photochemical reaction of W(CO)6 with bicyclo[2.2.1]hepta-2,5-diene (NBD) and GeCl4. The structure of compound 1 was established by X-ray crystallography. The IR, 1 H and 13 C NMR spectra are also described and correlated with the crystallographically observed geometry. Compound 1 is noteworthy since it is the first alkene complex of tungsten isolated in W(CO)6 – Lewis acid photocatalytic system.
Keywords: Tungsten; Germanium; Crystal structure; Heterobimetallic compound; Alkene complex;

Hydrothermal synthesis and X-ray powder structure determination of a novel layered tin(IV) phosphate, Sn(HPO4)2·(NH3)0.4(H2O)0.6 by Laura Roces; Sergei A. Khainakov; José R. Garcı́a; Pilar Pertierra; Miguel A. Salvadó; Santiago Garcı́a-Granda (685-689).
A novel layered tin(IV) phosphate, Sn(HPO4)2·(NH3)0.4(H2O)0.6, was synthesized under mild hydrothermal conditions. The unit cell is trigonal, a=4.9751(2)  A ̊ , c=22.5983(8)  A ̊ , space group R 3 ̄ , Z=3. The interlayer water and ammonia molecules are disordered and were both located on the same crystallographic site. This compound is the first example within the well-known family of α-metal(IV) phosphates of a non monoclinic phase stable at room temperature. The polymorphism of these compounds would explain several of the bibliographical discrepancies detected in the description of its physical–chemical properties.
Keywords: Phosphorus compounds; Tin compounds; Layered materials; Hydrothermal synthesis;

Synthesis and crystal structure of Cu(II) complex with 4-(pyridyl-2)-1,2,4-triazole by Olga G. Shakirova; Alexander V. Virovets; Dmitry Yu. Naumov; Yury G. Shvedenkov; Valentina N. Elokhina; Ludmila G. Lavrenova (690-693).
The synthesis and X-ray structure of new Cu(II) complex with 4-(pyridyl-2)-1,2,4-triazole (pytrz) are reported. The crystal structure of [Cu3(pytrz)8(H2O)4](NO3)6 has been determined by X-ray diffraction. Crystals are triclinic, space group P-1, unit cell parameters are: a=11.971(2), b=13.079(3), c=14.439(2)  A ̊ , α=114.03(1), β=97.79(1), γ=111.02(1)°, V=1819.2(6)  A ̊ 3 , Z=1, R f=0.0706. The structure consists of linear trinuclear cations with a +6 charge and six noncoordinated NO3 anions. The central copper(II) atom is located on an inversion centre and is coordinated by six nitrogen atoms of pytrz molecules bridging via the nitrogen atoms in the N 1,  N 2 positions. Each external copper(II) atom completes its coordination sphere with one monodentate pytrz via the nitrogen atom in the N1 position and two coordinated water molecules.
Keywords: Trinuclear complex; Copper(II); Triazole derivatives; Crystal structure;

A novel cesium–carborane cluster: synthesis and structure of [Cs5–(C2B9H12)4Cl] n by Aderemi R. Oki; Olga Sokolova; Blanca Gilbes; Ayodele Aduroja; Ghassan Abdelaziz; Thomas J. Emge (694-697).
The cage degradation reaction of closo 1,2-C2B10H12 carborane in the presence of 2-chloromethyl-4-nitro-phenol in alcoholic potassium hydroxide, followed by the addition of excess cesium chloride, produced a novel cesium carborane cluster, [Cs5–(C2B9H12)4Cl] n , 1. The compound crystallizes in the tetragonal space group I-4 with a=16.817(1) Å, b=16.817(1) Å, c=7.601(1) Å, V=2149.6(3)  A ̊ 3 , Z=8 and calculated density of 1.906 Mg/m3. The final refinement converged at R=0.018, based on 1142 unique reflections. There are two distinguishable type of cesium ions, Cs(1) is surrounded by four carborane cages and two Cl(1) ion, and Cs(2) is surrounded by five carborane cages and one Cl(1). The Cl occupies the center of a slightly distorted octahedral site Cs6Cl, with two Cl(1)–Cs(1) average distance of 3.84 Å and four Cl(1)–Cs(2) average distance of 3.64 Å. Each unit is then linked to another through a Cs(1)–Cl–Cs(1)–Cl repeating unit forming a polymeric chain.
Keywords: Carborane; Polymer; Cesium; Cage-degradation;

Reaction of Al(C6F5)3 with 0.34 equiv CH2Cl2 cleanly produces chlorobis(pentafluorophenyl)alane (C6F5)2AlCl, the dimeric structure in the solid-state of which has been confirmed by X-ray diffraction studies. This chloroalane exhibits remarkable activity in polymerizations of styrene, ε-caprolactone, and cyclohexene oxide.
Keywords: Alane; Organoalane; Polymerization catalysis; Catalyst;

Synthesis and structure of the first dinuclear lanthanide oxalato complexes [{MoV 2O4(C2O4)2(H2O)2}2{(Ln2(H2O)4)2(C2O4)}]·7H2O (Ln=La3+,Ce3+) by Pierre Mialane; Anne Dolbecq; Geoffrey Costaz; Laurent Lisnard; Jérôme Marrot; Francis Sécheresse (702-705).
Reaction between the [MoV 2O4(H2O)2(C2O4)2]2− anion and Ln III  (Ln=La,Ce) in water affords the isostructural neutral complexes [{MoV 2O4(C2O4)2(H2O)2}2{(Ln2(H2O)4)2(C2O4)}]. The structures have been solved by single-crystal X-ray diffraction and consist in a heteronuclear six-membered ring encapsulating an oxalate anion which connects the two rare earth cations. The formation of these complexes implies a partial decomposition of the precursor due to the high affinity of lanthanide toward oxalate in water which prevents the formation of analogous compounds with heavier rare earth cations in aqueous media.
Keywords: Lanthanide; Molybdenum; Oxalate;

Direct synthesis of a tetranuclear erbium(III) hydroxo cluster bearing a saturated Schiff base by Steve A. Schuetz; Victor W. Day; Joanna L. Clark; John A. Belot (706-710).
The reaction of bis-5,5-(2,2-dimethyl-1,3-propanediyldiimino)-2,2-dimethyl-4-hexen-3-one with tris[bis(trimethylsilyl)amido]erbium affords a five coordinate metal amido Schiff base (SB) complex which can be converted either stepwise or in situ into a neutral, tetranuclear Schiff base hydroxo cluster using H2O. Both complexes are reproducibly isolated in high yields with analytical purity and have been fully characterized. X-ray diffraction of the final hydrolysis product reveals a tetrameric [Er(μ3-OH)]4(SB)4 cubane structure with rigorous S4 symmetry. Each metal of the [Er(μ3-OH)]4 cube is also coordinated to a single tetradentate Schiff base in a monocapped trigonal prismatic arrangement.
Keywords: Lanthanide; Erbium; Schiff base; Tetranuclear; Hydroxo;

The self-assembly assisted by 2,2-bipyridine (2,2-bpy) protected zinc(II) species with 1,2-benzenedicarboxylate (1,2-BDC) has yielded a novel one-dimensional single helical coordination polymer of [Zn(2,2′-bpy)(1,2-BDC)(H2O)] n in a racemate of right- and left-handed helices, which was crystallographically studied and thermally analyzed.
Keywords: Self-assembly; Crystal structure; Zn(II) complex; Single helix coordination polymer;

Self-assembling mixed porphyrin trimers – the use of diaxial Sn(IV)porphyrin phenolates as an organising precept by Gary D. Fallon; Steven J. Langford; Marcia A.-P. Lee; Emmanuel Lygris (715-718).
Tin(IV)porphyrin phenolates are the stable product of the equilibrium-based condensation reaction of phenols with tin(IV)porphyrin dihydroxide in an organic medium. Their formation is characterised by significant shifts (1–5 ppm) of the phenolic protons within the recorded 1 H NMR spectra. To demonstrate the inherent simplicity of their formation and the flexibility in choice of phenolic ligand towards the design and fabrication of more elaborate assemblies and arrays we have constructed two different mixed porphyrin trimer families in which the porphyrin units differ in their orientation to the central porphyrin unit using Sn–O, Ru(III)–N and Zn(II)–N interactions. In one of these cases, 5 molecular components are self-assembled in one-pot to form a cofacially stacked mixed porphyrin trimer with high yield.
Keywords: Tin(IV) complexes; Ruthenium complexes; Zinc(II) complexes; Porphyrin;

Insights into the role of zinc(II) sites in hydrolytic enzymes: study of the ZnII/X/(py)2CO (X=Cl, N3 , SO4 2−; (py)2 COdi-2-pyridyl ketone ) reaction systems by Eugenia Katsoulakou; Nikolia Lalioti; Catherine P. Raptopoulou; Aris Terzis; Evy Manessi-Zoupa; Spyros P. Perlepes (719-723).
A bioinorganic model approach for the investigation of substrate activation by zinc active sites in hydrolytic enzymes has been initiated. Several reaction schemes involving the substrate analogue di-2-pyridyl ketone, (py)2CO, and Zn(II) sources afforded the new complexes [ZnCl 2{(py)2 CO}]( 1 ), [ZnCl 2{(py)2 C(OMe)(OH)}]( 2 ), [Zn 2 Cl 2{(py)2 C(OMe)O}2]( 3 ), [Zn 2(N 3)2{(py)2 C(OMe)O}2]( 4 ) and [Zn 2(SO 4)2{(py)2 C(OMe)(OH)}2(MeOH)2]( 5 ), which have been characterized by single-crystal X-ray crystallography and spectroscopic techniques. The chemical and structural identity of the products depends on the solvent, the hydroxide concentration and the nature of the inorganic anion. The biological relevance of the prepared complexes is also discussed.
Keywords: Bioinorganic chemistry; Crystal structures; Di-2-pyridyl ketone; Zinc complexes; Zinc sites in hydrolytic enzymes;

The new pyridylimine complex, {N-dodecyl-N-[(1E)-pyridin-2-ylmethylene]amine}dichloro palladium was synthesized by the reaction of N-(dodecanyl)pyridyl-2-methanimine with (COD)PdCl2. The complex when activated with methylaluminoxane polymerizes ethylene to produce only high-density polyethylene under mild reaction conditions.
Keywords: Palladium; Pyridylimine; Ethylene polymerization; Polyethylene; Pyridyl-2-methanimine;

Text and pictogram for subject index entry: The structural study of [Ni(ADA)(bipy)(H2O)]·4H2O (ADA =  N-(carbamoylmethyl)iminodiacetato(2−) ligand) reveals an unexpected ADA-tridentate role, with a free N-(2-amidomethyl) arm. That is in contrast to the tripodal–tetradentate ADA2− reported for all metal–ADA complexes of known structures and is explained by ligand conformation comparison in three Ni(II)–ADA chelates.The crystal structure of a new mixed-ligand nickel(II) complex of N-(carbamoylmethyl)iminodiacetato(2−) (ADA) and 2,2-bipyridine (bipy), with formula [Ni(ADA)(bipy)(H2O)]·4H2O (compound 3), reveals an unexpected tridentate ADA ligand, with a free N-(2-amidomethyl) arm, in contrast with all other known structures of metal–ADA chelates which have ADA2− as tripodal–tetradentate ligand. This finding is explained on the basis of a structural comparison with the compounds of [Ni(ADA)(H2O)2] (1) and [Ni(ADA)( Him )(H 2 O)]·1.5H 2 O (2, Him = imidazole) which reveals significant changes in Ni–N(amino tertiary) and Ni–O(amide) bond lengths as well as in the ADA denticity and ligand conformation concerning the iminodiacetato(2−) moiety (IDA) in these Ni(II) chelates. The ADA-ligand conformation is mer-IDA + O(amide), fac-IDA + O(amide) or only fac-IDA-tridentate in 1, 2 or 3 respectively.
Keywords: Ligand conformation; Denticity; Amide; Iminodiacetate; Bipyridine; Nickel complex;

The photolysis of FeIII(et2dtc)3 with et2dtc  = diethyldithiocarbamate in inert solvents (e.g., CH3CN) and in the presence of 1,2-bis(diphenylphosphino)ethane (dppe) leads to the formation of FeII(et2dtc)2(dppe) and (et2dtc)2  = tetraethylthiuramdisulfide. At equimolar concentrations (2.76×10−5 M) of FeIII(et2dtc)3 and dppe the quantum yields are φ=0.007 at λ irr =333  nm and 0.003 at 436 nm. This photoreaction, which is initiated by ligand-to-metal charge transfer excitation, generates FeII(et2dtc)2 and a et2dtc radical in the primary photochemical step. Product formation occurs by the interception of FeII(et2dtc)2 with dppe.
Keywords: Electronic Spectra; Charge transfer; Photochemistry; Iron complexes; Sulfur compounds;

N,N-dialkylcarbamato metal complexes, molecular inorganic precursors to functionalized inorganic matrices by Daniela Belli Dell' Amico; Fausto Calderazzo; Luca Labella; Fabio Marchetti; Guido Pampaloni (733-745).
Keywords: N,N-dialkylcarbamates; Homoleptic derivatives; Polynuclear complexes; Functionalized surfaces;