New chloro- and trifluoroacetato tricarbonylrhenium(I) complexes with a N,N′-bis(benzophenone)-1,2-diiminoethane Schiff base ligand: Spectral and structural studies

The reaction of Re(CO)₅Cl with the chelating ligand N,N′-bis(benzophenone)-1,2-diiminoethane (bz₂en) afforded the neutral fac-[Re(CO)₃(bz₂en)Cl]. The subsequent reaction with AgOCOCF₃ gave fac-[Re(CO)₃(bz₂en)OCOCF₃]. Their pseudooctahedral fac structures have been established by FTIR, UV–Vis, ¹H, ¹³C NMR and have been confirmed by X-ray diffraction analysis. The electrochemical behaviour of the investigated complexes has been studied by cyclic voltammetry.     

Structural comparison of group 7 tricarbonyl complexes of 2‐{[2‐(1H‐imidazol‐4‐yl)ethyl]iminomethyl}‐5‐methylphenolate

Two tricarbonyl complexes of rhenium(I) and manganese(I) coordinated by the ligand 2‐{[2‐(1H‐imidazol‐4‐yl)ethyl]iminomethyl}‐5‐methylphenolate are reported, viz. fac‐tricarbonyl(2‐{[2‐(1H‐imidazol‐4‐yl‐κN³)ethyl]iminomethyl‐κN}‐5‐methylphenolato‐κO)rhenium(I) methanol monosolvate, [Re(C₁₆H₁₄N₃O₄)(CO)₃]·CH₃OH, (I), and fac‐tricarbonyl(2‐{[2‐(1H‐imidazol‐4‐yl‐κN³)ethyl]iminomethyl‐κN}‐5‐methylphenolato‐κO)manganese(I), fac‐[Mn(C₁₆H₁₄N₃O₄)(CO)₃], (II), display facial coordination in a distorted octahedral environment. The crystal structure of (I) is stabilized by O—H...O, N—H...O and C—H...O hydrogen‐bond interactions, while that of (II) is stabilized by N—H...O hydrogen‐bond interactions only. These interactions result in two‐dimensional networks and π–π stacking for both structures.     

Synthesis, spectroscopic properties and crystal structure of mononuclear tricarbonylrhenium(I) chloride complexes carrying 6-functionalised quinoxalines

Two quinoxaline derivatives pqCH₃ and pqCl (where pq stands for 2-(2′-pyridyl)quinoxaline) were prepared by condensation of 2-acetyl pyridyl with 2-amino-4-methylphenylamine or 2-amino-4-chlorophenylamine, correspondingly and were studied spectroscopically and electrochemically, in correlation with the originally reported pq. Their novel corresponded complexes namely, fac-[Re(CO)₃Cl(L)] (where L = pqCH₃2 and pqCl 3) were synthesized, characterized, studied and compared to Re(CO)₃Clpq, 1. Complex 2 crystallizes in space group C2/c with a = 20.4476(17) Å, b = 15.4521(13) Å, c = 15.2887(13) Å, β = 126.1210(11)°, Z = 8 and V = 3902.0(6) Å³. The substitution of -H by -CH₃ or -Cl at 6-position of pq has a minor electronic effect on the pyridyl ring of the ligands, but seems to influence the quinoxaline moiety enough to alter the spectroscopical and electrochemical features.     

二维网状银(I)配合物的合成及结构表征

用1,10-二(邻氨基苯氧基)癸烷和AgNO3,进行配位反应得到了配合物[Ag2(L)(NO3)2]η(1).并用元素分析,FT-IR和X-射线单晶衍射进行了表征.结果表明,配合物属于单斜晶系,P21/c空间群,晶胞参数为:a=0.5649(l)nm,b=3.3426(7)nm,c=0.9375 (2) nm,β=99...     

Synthesis,crystal structures and spectral properties of cobalt (Ⅱ) complexes:[ CoL (N_3) ] ·ClO_4 and CoL (N_3)_2 [L=tris ((3,5-dimethylpyrazol-1-yl) methyl) amine

Two monomeric cobalt(Ⅱ)complexes,[CoL(N3)] ClO4(1)and CoL(N3)2(2),where L is tris((3,5-dimethylpyrazol-1-yl)methyl)amine,were synthesized and their crystal structures were determined by X-ray diffraction technique.Complex 1 is five coordinated with one azide nitrogen atom and four nitrogen atoms of the tris((3,5-dimethylpyrazol-l-yl)-methyl)amine ligand,and the metal center is in distorted trigonal bipyramidal environment.Complex 2 is six coordinated distorted octahedron with the two azide nitrogen atoms and four nitrogen donors of the tris((3,5-dimethylpyrazol-1-yl)-methyl)amine ligand.The solution behaviors of the title complexes have been further investigated by UV-Vis,and 1H NMR analysis.It is found that the formation of 1 and 2 depends on the molar ratio of the azide ion to metal salt and ligand Complex 1 attached with one azide group is more stable and easy to generate than complex 2 incorporated with two azide groups,and the reasons were well discussed.     

Copper(I) bromide and chloride complexes with urotropine and triethylenediamine: synthesis,crystal structure,and Raman characterization*

Abstract

In the present study, the oxidative dissolution of metallic copper has been explored with the intention to prepare some new complexes with urotropine (hmta) and triethylenediamine (dabco) ligands. All the compounds synthesized were characterized by single-crystal X-ray diffraction and Raman spectroscopy. Reactions performed in a DMSO/CuCl₂?2H₂O mixture resulted in [(μ-Cl)₂Cu^I(hdabco⁺)Cu^I(μ-Cl)(κS-DMSO)]_n and [Cu^ICl(hmta)₂] complexes. Their isostructural bromide analogs [(μ-Br)₂Cu^I(hdabco⁺)Cu^I(μ-Br)(κS-DMSO)]_n and [Cu^IBr(hmta)₂] were prepared by the reaction of elemental copper with respective ligands in a DMSO/CBr₄ mixture. Early interrupted reaction of the copper wire with the DMSO/CBr₄/dabco solution resulted in an appearance of crystals of the [Cu^I₂Br₂(CO)₂(dabco)]_n carbonyl complex on the copper surface. It arises with the participation of in situ formed carbon monoxide. Despite the identical stoichiometry, the crystal structure of the [Cu₂Br₂(CO)₂(dabco)]_n complex is markedly different from that of a known [Cu₂Cl₂(CO)₂(dabco)]_n analog.     

Oxidative degradation of the organometallic iron(II) complex [Fe{bis[3‐(pyridin‐2‐yl)‐1H‐imidazol‐1‐yl]methane}(MeCN)(PMe3)](PF6)2: structure of the ligand decomposition product trapped via coordination to iron(II)

Iron is of interest as a catalyst because of its established use in the Haber–Bosch process and because of its high abundance and low toxicity. Nitrogen‐heterocyclic carbenes (NHC) are important ligands in homogeneous catalysis and iron–NHC complexes have attracted increasing attention in recent years but still face problems in terms of stability under oxidative conditions. The structure of the iron(II) complex [1,1′‐bis(pyridin‐2‐yl)‐2,2‐bi(1H‐imidazole)‐κN³][3,3′‐bis(pyridin‐2‐yl‐κN)‐1,1′‐methanediylbi(1H‐imidazol‐2‐yl‐κC²)](trimethylphosphane‐κP)iron(II) bis(hexafluoridophosphate), [Fe(C₁₇H₁₄N₆)(C₁₆H₁₂N₆)(C₃H₉P)](PF₆)₂, features coordination by an organic decomposition product of a tetradentate NHC ligand in an axial position. The decomposition product, a C—C‐coupled biimidazole, is trapped by coordination to still‐intact iron(II) complexes. Insights into the structural features of the organic decomposition products might help to improve the stability of oxidation catalysts under harsh conditions.     

Ionothermal synthesis and crystal structure of a new organic–inorganic hybrid compound: catena‐poly[bis(1‐ethyl‐3‐methylimidazolium) [hepta‐μ‐bromido‐pentacuprate(I)]]

A new organic–inorganic hybrid compound, catena‐poly[bis(1‐ethyl‐3‐methylimidazolium) [μ₅‐bromido‐tri‐μ₃‐bromido‐tri‐μ₂‐bromido‐pentacuprate(I)]], {(C₆H₁₁N₂)₂[Cu₅Br₇]}_n, has been obtained under ionothermal conditions from a reaction mixture containing Ba(OH)₂·8H₂O, Cu(OH)₂·2H₂O, As₂O₅, 1‐ethyl‐3‐methylimidazolium bromide and distilled water. The crystal structure consists of complex [Cu₅Br₇]²⁻ anions arranged in sinusoidal {[Cu₅Br₇]²⁻}_n chains running along the a axis, which are surrounded by 1‐ethyl‐3‐methylimidazolium cations. Three of the five unique Br atoms and one of the three Cu^I atoms occupy special positions with half‐occupancy (a mirror plane perpendicular to the b axis, site symmetry m). The Cu^I ions are in a distorted tetrahedral coordination environment, with four Br atoms at distances ranging from 2.3667 (10) to 2.6197 (13) Å, and an outlier at 3.0283 (12) Å, exceptionally elongated and with a small contribution to the bond‐valence sum of only 6.7%. Short C—H...Br contacts build up a three‐dimensional network. The Cu...Cu distances within the chain range from 2.8390 (12) to 3.0805 (17) Å, indicating the existence of weak Cu^I...Cu^I cuprophilic interactions.     

Synthesis,crystal structure and spectroscopic properties of trans‐dibromidobis(2,2‐dimethylpropane‐1,3‐diamine‐κ2N,N′)chromium(III) perchlorate

The title complex salt, trans‐anti‐[CrBr₂(Me₂tn)₂]ClO₄ (where Me₂tn = 2,2‐dimethylpropane‐1,3‐diamine, C₅H₁₄N₂), was prepared and its structure determined by single‐crystal X‐ray diffraction at 100 K. The asymmetric unit contains three conformationally similar complex cations and three perchlorate anions. In each complex cation, the Cr^III centre is coordinated by four N atoms of two chelating Me₂tn ligands in the equatorial plane and by two Br atoms in a trans‐axial arrangement, to give a distorted octahedral geometry. Interionic contacts are dominated by extensive hydrogen bonding, involving the NH groups of the Me₂tn ligand as donors and the anion O atoms or coordinated Br atoms as acceptors, resulting in two‐dimensional layers in the bc plane. Ligand field analysis based on the angular overlap model, and IR and electronic spectroscopic properties, are also discussed.     

Synthesis,Characterization and Crystal Structure of Dimeric {[(AMTTO)2Ag]NO3}2 (AMTTO = 4‐Amino‐6‐methyl‐1, 2, 4‐triazine‐3(2H)‐thione‐5‐one)

The reaction of 4‐Amino‐6‐methyl‐1, 2, 4‐triazine‐3(2H)‐thione‐5‐one (AMTTO, 1 ) with silver nitrate in methanol led to the dimeric complex {[(AMTTO)₂Ag]NO₃}₂ ( 2 ). 2 was characterized by elemental analyses and IR spectroscopy as well as by X‐ray structure analysis. Crystal data for 2 at ?80 °C: crystal system orthorhombic, space group P2₁2₁2₁ with a = 1043.6(1), b = 1329.6(1), c = 2358.4(1) pm, Z = 8 and R₁ = 0.037. The cation possesses a highly distorted linear coordination sphere in the solid state.     

The molecular structure of high‐spin (S = ) manganese(II) phthalocyanine in tetrabutylammonium bromido(phthalocyaninato)manganese(II)

The title complex salt, (C₁₆H₃₆N)[MnBr(C₃₂H₁₆N₈)] or (TBA)[Mn^IIBr(Pc)] (TBA is tetrabutylammonium and Pc is phthalocyaninate), has been obtained as single crystals by the diffusion technique and its crystal structure was determined using X‐ray diffraction. The high‐spin (S = ) [Mn^IIBr(Pc)]⁻ macrocycle has a concave conformation, with an average equatorial Mn—N(Pc) bond length of 2.1187 (19) Å, an axial Mn—Br bond length of 2.5493 (7) Å and with the Mn^II cation displaced out of the 24‐atom Pc plane by 0.894 (2) Å. The geometry of the Mn^IIN₄ fragment in [Mn^IIBr(Pc)]⁻ is similar to that of the high‐spin (S = ) manganese(II) tetraphenylporphyrin (TPP) in [Mn^II(1‐MeIm)(TPP)] (1‐MeIm is 1‐methylimidazole).     

Synthesis and Crystal Structure of a New Silver(I) Complex

The reaction of 4-amino-6-methyl-1,2,4-triazine-3(2 H)-thione-5-one (AMTTO) with silver(I) nitrate in methanol gives the complex [Ag(AMTTO)₂]NO₃ ( 1 ). 1 was characterized by IR and ¹³C NMR spectroscopy and by an X-ray structure analysis [space group C2/c, Z = 4, lattice dimensions at –80 °C: a = 1306.7(2), b = 1139.0(2), c = 1089.2(1) pm, β = 94.54(1)°, R₁ = 0.0294]. The cation possesses a highly distorted linear coordination sphere in the solid state.     

`0'‐ and `8'‐shaped complexes generated from a nano‐sized oxadiazole‐containing organic ligand with CdI2 and CuI

A new nano‐sized rigid double‐armed oxadiazole‐bridged organic ligand, 2,5‐bis{2‐methyl‐5‐[2‐(pyridin‐3‐yl)ethenyl]phenyl}‐1,3,4‐oxadiazole, C₃₀H₂₀N₄O, L or (I), which adopts a cis conformation in the solid state, has been synthesized and used to create the two novel metallocycle complexes (2,5‐bis{2‐methyl‐5‐[2‐(pyridin‐3‐yl‐κN)ethenyl]phenyl}‐1,3,4‐oxadiazole)diiodidocadmium(II) dichloromethane monosolvate, [CdI₂(C₃₀H₂₀N₄O)]·CH₂Cl₂, (II), and di‐μ‐iodido‐bis[(2,5‐bis{2‐methyl‐5‐[2‐(pyridin‐3‐yl‐κN)ethenyl]phenyl}‐1,3,4‐oxadiazole)copper(I)], [Cu₂I₂(C₃₀H₂₀N₄O)₂], (III). Molecules of complex (II) adopts a 20‐membered `0'‐shaped metallocycle structure with crystallographic mirror symmetry. The discrete units are linked into one‐dimensional chains through intermolecular π–π and C—H...π interactions. In (III), the two I atoms and two Cu<sup>I</sup> atoms form a {Cu<sub>2</sub>(μ‐I)<sub>2</sub>} cluster. One {Cu<sub>2</sub>(μ‐I)<sub>2</sub>} cluster and two L ligands form two 20‐membered monometallic rings in a head‐to‐head fashion, leading to a discrete centrosymmetric `8'‐shaped metallocyclic complex. These metallocycles stack together via two kinds of intermolecular π–π interactions to generate a two‐dimensional network in the ac plane. The luminescence properties of (I)–(III) were investigated in the solid state at room temperature and displayed an obvious red shift.     

The crystal structure,luminescence and nitrobenzene‐sensing properties of a two‐dimensional MnII coordination polymer based on 2,6‐bis(imidazol‐1‐yl)pyridine

A two‐dimensional Mn^II coordination polymer (CP), poly[bis[μ₂‐2,6‐bis(imidazol‐1‐yl)pyridine‐κ²N³:N^3′]bis(thiocyanato‐κN)manganese] [Mn(NCS)₂(C₁₁H₉N₅)₂]_n, (I), has been obtained by the self‐assembly reaction of Mn(ClO₄)₂·6H₂O, NH₄SCN and bent 2,6‐bis(imidazol‐1‐yl)pyridine (2,6‐bip). CP (I) was characterized by FT–IR spectroscopy, elemental analysis and single‐crystal X‐ray diffraction. The crystal structure features a unique two‐dimensional (4,4) network with one‐dimensional channels. The luminescence and nitrobenzene‐sensing properties were explored in a DMF suspension, revealing that CP (I) shows a strong luminescence emission and is highly sensitive for nitrobenzene detection.     

Counter‐anion role in the formation of two supramolecular complexes: [Ag2(DPP)2](ClO4)2·CH3CN and [Ag2(DPP)2(NO3)2] {DPP is N‐[(diphenylphosphanyl)methyl]pyridin‐4‐amine}

The title compounds, bis{μ‐N‐[(diphenylphosphanyl)methyl]pyridin‐4‐amine‐κ²N¹:P}disilver bis(perchlorate) acetonitrile monosolvate, [Ag₂(C₁₈H₁₇N₂P)₂](ClO₄)₂·CH₃CN, (1), and bis{μ‐N‐[(diphenylphosphanyl)methyl]pyridin‐4‐amine‐κ²N¹:P}bis[(nitrato‐κ²O,O)silver], [Ag₂(C₁₈H₁₇N₂P)₂(NO₃)₂], (2), each contain disilver macrocyclic [Ag₂(C₁₈H₁₇N₂P)₂]²⁺ cations lying about inversion centres. The cations are constructed by two N‐[(diphenylphosphanyl)methyl]pyridin‐4‐amine (DPP) ligands linking two Ag⁺ cations in a head‐to‐tail fashion. In (1), the unique Ag⁺ cation has a near‐linear coordination geometry consisting of one pyridine N atom and one P atom from two different DPP ligands. Two ClO₄⁻ anions doubly bridge two metallomacrocycles through Ag...O and N—H...O weak interactions to form a chain extending in the c direction. The half‐occupancy acetonitrile molecule lies with its methyl C atom on a twofold axis and makes a weak N...Ag contact. In (2), there are two independent [Ag(C₁₈H₁₇N₂P)]⁺ cations. The nitrate anions weakly chelate to each Ag⁺ cation, leading to each Ag⁺ cation having a distorted tetrahedral coordination geometry consisting of one pyridine N atom and one P atom from two different DPP ligands, and two chelating nitrate O atoms. Each dinuclear [Ag₂(C₁₈H₁₇N₂P)₂(NO₃)₂] molecule acts as a four‐node to bridge four adjacent equivalent molecules through N—H...O interactions, forming a two‐dimensional sheet parallel to the bc plane. Each sheet contains dinuclear molecules involving just Ag1 or Ag2 and these two types of sheet are stacked in an alternating fashion. The sheets containing Ag1 all lie near x = , , etc, while those containing Ag2 all lie near x = 0, 1, 2 etc. Thus, the two independent sheets are arranged in an alternating sequence at x = 0, , 1, etc. These two different supramolecular structures result from the different geometric conformations of the templating anions which direct the self‐assembly of the cations and anions.     

The exopolyhedral ligand orientation (ELO) in 3‐(nitrato‐κO)‐3,3‐bis(triphenylphosphane‐κP)‐3‐rhoda‐1,2‐dicarba‐closo‐dodecaborane(11) dichloromethane 2.2‐solvate

In the title compound, [Rh(C₂H₁₁B₉)(NO₃)(C₁₈H₁₅P)₂]·2.2CH₂Cl₂, studied as a 2.2‐solvate of what was assumed to be dichloromethane, the nitrate ligand lies cis with respect to both cage C atoms. Accordingly, the compound displays a pronounced preferred exopolyhedral ligand orientation (ELO) which is traced to both the greater trans influence of the cage B over the cage C atoms and the greater trans influence of the triphenylphosphane ligands over the nitrate ligand. The overall molecular architecture therefore agrees with that of a number of similar 3‐L‐3,3‐L′₂‐3,1,2‐closo‐MC₂B₉H₁₁ species in the literature.     

Synthesis,crystal structure and magnetic properties of the binuclear copper (II) complex of a new bis (1, 4, 7, 10‐tetraazacyclododecane) ligand

A new binucleating macrocyclic ligand 2,6‐bis (1,4,7,10‐tetraazacyclododecan‐10‐ylmethyl) methoxy‐benzene (L) and its binuclear copper (II) complex, [Cu₂LBr₂] (CIO₄ )₂ · 3H₂O (1), was prepared and the structure was determined by X‐ray crystallography. Complex 1 crystallizes in monoclinic crystal system, P2₁/n space group with a = 0.8206(3), b =2.0892(8), c = 2.3053(7) mn, β = 95.83(2)°, V = 3.932 nm³, Mr=1017.57, Z = 4, D_c =1.692 g/cm³, and R= 0.0489, R_w 0.0552 for 6571 observed reflections with I ≥ 2σ (1). Both of the copper(II) centers are coordinated by four amine nitrogen donors of cyclen subunits and a bromide anion, and each copper(II) ion is in a square‐pyramidal coordination environment. Variable temperature magnetic susceptibility studies indicate that there exists weak intramolecular antiferro‐magnetic coupling ( ?2J = 2.06 cm^?1) between the two copper (II) centers.     

Syntheses and Crystal Structures of Two Silver(I) Complexes Isolated by the Reaction of [Ag(PPh3)2(MeCN)](SbF6) with a N6 Ligand

1 INTRODUCTION The polyaza macrocyclic and macrobicyclic mo-lecules have been extensively studied due to theirinclusion ability for neutral molecules, coordinationability for metal cations and versatile roles in thefields of recognition, transformation…     

Synthesis and crystal structure of 2‐amino‐3‐hydroxypyridinium dioxido(pyridine‐2,6‐dicarboxylato‐κ3O2,N,O6)vanadate(V) and its conversion to nanostructured V2O5

2‐Amino‐3‐hydroxypyridinium dioxido(pyridine‐2,6‐dicarboxylato‐κ³O²,N,O⁶)vanadate(V), (C₅H₇N₂O)[V(C₇H₃NO₄)O₂] or [H(amino‐3‐OH‐py)][VO₂(dipic)], (I), was prepared by the reaction of VCl₃ with dipicolinic acid (dipicH₂) and 2‐amino‐3‐hydroxypyridine (amino‐3‐OH‐py) in water. The compound was characterized by elemental analysis, IR spectroscopy and X‐ray structure analysis, and consists of an anionic [VO₂(dipic)]⁻ complex and an H(amino‐3‐OH‐py)⁺ counter‐cation. The V^V ion is five‐coordinated by one O,N,O′‐tridentate dipic dianionic ligand and by two oxide ligands. Thermal decomposition of (I) in the presence of polyethylene glycol led to the formation of nanoparticles of V₂O₅. Powder X‐ray diffraction (PXRD) and scanning electron microscopy (SEM) were used to characterize the structure and morphology of the synthesized powder.