Diverse coordination of two ligands in ferromagnetic [Cu(μ-HCO2)2(3-pyOH)]n and [Cu2(μ-HCO2)2(μ-3-pyOH)2(3-pyOH)2(HCO2)2]n

Two novel polynuclear complexes with methanoate anions and 3-hydroxypyridine ligands [Cu(μ-HCO₂)₂(3-pyOH)]_n (1) and [Cu₂(μ-HCO₂)₂(μ-3-pyOH)₂(3-pyOH)₂(HCO₂)₂]_n (2), respectively, were synthesized and characterized. The central copper atom in 1 is surrounded by four methanoates and a 3-pyOH molecule, forming a square-pyramidal CuO₃NO chromophore. All the methanoates are bidentate and serve as bridges between the adjacent copper ions via syn-anti and anti–anti coordination. The basal square coordination axes are formed by O(syn), N(3-pyOH) (1.974(2), 2.016(2) Å) and O(anti), O(anti) (1.945(2), 1.960(2) Å), while the third O(anti) (2.247(2) Å) is on the top of the pyramid. A ferromagnetic transition with an exchange constant 2J/k_B = 9.2 cm⁻¹ is found for 1 below 20 K. This interaction probably takes place through two syn-anti methanoates extended in a chain through the 2D structure. On the other hand, two monoatomic Cu–O–Cu intra-dinuclear asymmetric (1.986(2), 2.415(2) Å) bridges of two methanoates in [Cu₂(HCO₂)₄(3-pyOH)₄] (2) are present. An elongated distorted octahedral coordination sphere around each copper(II) atom is completed by an additional monodentate terminal methanoate (1.975(2) Å), two N-coordinated 3-pyOH (2.005(2), 2.002(2) Å) and the third weakly O-coordinated 3-pyOH (2.732(2) Å). Although a shorter Cu?Cu distance is noticed in 2 than in 1 (4.690(1) Å 1, 3.442(1) Å 2), much weaker ferromagnetism is found in 2.     

[COH(NH2)2]2[Cu(pic)2(ClO4)2]的合成与晶体结构

The title compound was synthesized by reaction of Cu(ClO₄)₂， picolinic acid and carbamide in C₂H₅OH/CH₃CN solution， and characterized by single-crystal X-ray diffraction. It crystallizes in the orthorhombic system， space group Pbca with a=14.0481(8)， b=9.0130(5)， c=18.626(1)?， V=2358.3(2)?³， Z=4， D_x=1.771g·cm^-3， μ=1.235mm^-1 and F(000)=1276. The final R factor is 0.0440 for 1434 observed reflections. The X-ray analysis revealed that the copper(Ⅱ) atom is coordinated by two picolinic ligands in the equatorial plane， while the two oxygen atoms of perchlorate occupy the axial positions of octahedron with lengthened Cu-O distances， resulting in a 4+2 elongated octahedral environment. In the compound， there also exist two protonated carbamide cations for charge balance. CCDC： 195354.     

Hydrothermal synthesis and crystal structures of new uranyl oxalate hydroxides: α- and β-[(UO2)2(C2O4)(OH)2(H2O)2] and [(UO2)2(C2O4)(OH)2(H2O)2]·H2O

Two modifications of the new uranyl oxalate hydroxide dihydrate [UO₂)₂(C₂O₄)(OH)₂(H₂O)₂] (1 and 2) and one form of the new uranyl oxalate hydroxide trihydrate [(UO₂)₂(C₂O₄)(OH)₂(H₂O)₂]·H₂O (3) were synthesized by hydrothermal methods and their structures determined from single-crystal X-ray diffraction data. The crystal structures were refined by full-matrix least-squares methods to agreement indices R(wR)=0.0372(0.0842) and 0.0267(0.0671) calculated for 1096 and 1167 unique observed reflections (I>2σ(I)), for α (1) and β (2) forms, respectively and to R(wR)=0.0301(0.0737) calculated for 2471 unique observed reflections (I>2σ(I)), for 3. The α-form of the dihydrate is triclinic, space group , Z=1, a=6.097(2), b=5.548(2), , α=89.353(5), β=94.387(5), γ=97.646(5)°, , β-form is monoclinic, space group C2/c, Z=4, a=12.180(3), b=8.223(2), , β=95.817(4), . The trihydrate is monoclinic, space group P2₁/c, Z=4, a=5.5095(12), b=15.195(3), , β=93.927(3), . In the three structures, the coordination of uranium atom is a pentagonal bipyramid composed of dioxo UO₂²⁺ cation perpendicular to five equatorial oxygen atoms belonging to one bidentate oxalate ion, one water molecule and two hydroxyl ions in trans configuration in 2 and in cis configuration in 1 and 3. The UO₇ polyhedra are linked through hydroxyl oxygen atoms to form different structural building units, dimers [U₂O₁₀] obtained by edge-sharing in 1, chains [UO₆]_∞ and tetramers [U₄O₂₆] built by corner-sharing in 2 and 3, respectively. These units are further connected by oxalate entities that act as bis-bidentate to form one-dimensional chains in 1 and bi-dimensional network in 2 and 3. These chains or layers are connected in frameworks by hydrogen-bond arrays.     

Synthesis of dipyrrolo[2,3-a:1′,2′,3′-fg]acridin-12(1H)-ones

Acylation reactions of 4,6-dimethoxyindoles with glyoxyloyl chlorides were achieved by the use of graphite powder in 1,2-dichloroethane at reflux. The products were monoketones as a result of decarbonylation, rather than the expected 1,2-diketones. Treatment of these monoketones with base led to their cyclisation and elimination of methanol to afford the novel dipyrrolo[2.3-a:1′,2′,3′-fg]acridin-12(1H)-ones.     

Synthesis and structures of Cs4[(UO2)2(C2O4)(SO4)2(NCS)2] · 4H2O and (NH4)4[(UO2)2(C2O4)(SO4)2(NCS)2] · 6H2O

Single crystals of Cs₄[(UO₂)₂(C₂O₄)(SO₄)₂(NCS)₂] · 4H₂O (I) and (NH₄)₄[(UO₂)₂(C₂O₄)(SO₄)₂(NCS)₂] · 6H₂O (II) have been synthesized and studied by X-ray diffraction. The crystals of both compounds are orthorhombic with the space group Pbam, Z = 2, and unit cell parameters a = 12.0177(3) ?, b = 18.6182(5) ?, c = 6.7573(10) ?, R = 0.0376 (I); a = 11.6539(9) ?, b = 18.3791(13) ?, c = 6.7216(5) ?, R = 0.0179 (II). The main structural units of crystals I and II are [(UO₂)₂(C₂O₄)(SO₄)₂(NCS)₂]⁴⁻ chains belonging to the crystal-chemical group A₂K⁰²B₂²M₂¹ (A = UO₂²⁺, K⁰² = C₂O₄²⁻, B² = SO₄²⁻, M¹ = NCS⁻) of the uranyl complexes. The uranium-containing chains are joined into a three-dimensional framework due to a system of electrostatic interactions with the cesium or ammonium ions in the structure of I. In the structure of II, this framework is additionally stabilized by hydrogen bonds involving the outer-sphere water molecules and ammonium ions. Original Russian Text ? I.V. Medrish, A.V. Virovets, E.V. Peresypkina, L.B. Serezhkina, 2008, published in Zhurnal Neorganicheskoi Khimii, 2008, Vol. 53, No. 7, pp. 1115–1120.     

Synthesis and crystal structure of new one-dimensional copper(II) complex [Cu4(En)2(μ1,1-N3)4(μ1,1,1-N3)2(μ1,3-N3)2]n

A new polymer azido-bridged copper(II) complex [Cu₄(En)₂(μ_1,1-N₃)₄(μ_1,1,1-N₃)₂(μ_1,3-N₃)₂] _n (I) (En = ethylenediamine) has been synthesized and crystallography characterized. Complex I shows one-dimensional coordination polymeric structure based on a tetranuclear cluster unit [Cu₄(En)₂(μ_1,1-N₃)₄(μ_1,1,1-N₃)₂(μ_1,3-N₃)₂], in which the azido ions display three different bridging modes.     

Stepwise addition of CuBr at [(dtc)2Mo2(S)2(μ-S)2] (dtc=diethyldithiocarbamate): syntheses and crystal structures of two Mo/Cu/S clusters [(dtc)2Mo2(μ3-S)(μ-S)3(CuBr)] and [(dtc)2Mo2(μ3-S)4(CuBr)2]

Reactions of [(dtc)₂Mo₂(S)₂(μ-S)₂] with one or two equivalents of CuBr in CH₂Cl₂ afforded two new heterobimetallic sulfide clusters, [(dtc)₂Mo₂(μ₃-S)(μ-S)₃(CuBr)] (1) and [(dtc)₂Mo₂(μ₃-S)₄(CuBr)₂] (2). Both compounds were characterized by elemental analysis, IR, UV-vis and X-ray analysis. Compound 1 contains a butterfly-shaped Mo₂S₄Cu core in which one CuBr unit is coordinated by one bridging S and two terminal S atoms of the [(dtc)₂Mo₂(S)₂(μ-S)₂] moiety. In the structure of 2, one [(dtc)₂Mo₂(S)₂(μ-S)₂] moiety and two CuBr units are held together by six Cu-μ₃-S bonds, forming a cubane-like Mo₂S₄Cu₂ core.     

Synthesis,structure characterization and thermal properties of [Zr6(μ3-O)4(μ3-OH)4(OOCCH2Bu)9(μ2-OH)3]2

Oxo/hydoxo zirconium(IV) complex of the general formula [Zr₆(μ₃-O)₄(μ₃-OH)₄(OOCCH₂^tBu)₉(μ₂-OH)₃]₂ has been isolated, when Zr(OⁱPr)₄ reacted with a 2-fold excess of 3,3-dimethylbutyric acid. Single crystal X-ray diffraction data, collected at 103 and 153 K, showed that the studied compound crystallizes in hexagonal system (P6₃/m (no. 176)). Structure consists of dimers composed of [Zr₆(μ₃-O)₄(μ₃-OH)₄(OOCCH₂^tBu)₉] sub-units, linked by six μ₂-OH bridges. Infrared spectroscopic studies proved the presence of hydroxo groups in the structure of studied clusters and formation of different types of oxo/hydroxo bridges. The application of variable temperature infrared spectroscopy and differential scanning calorimetry revealed that the structure of this complex undergoes the phase transitions at 143–183 and 203–293 K. Comparison of spectral and crystallographic data suggests that these phase transitions might be related to changes in the strength of Zr–O bonds of μ₂-OH bridges linking complex sub-units, and change in symmetry of the crystal lattice (from hexagonal to trigonal). Analysis of thermogravimetric data showed that decomposition of [Zr₆(μ₃-O)₄(μ₃-OH)₄(OOCCH₂^tBu)₉(μ₂-OH)₃]₂ proceeds with complete conversion to ZrO₂ (monoclinic form) between 603 and 803 K.     

Synthesis of Mo(CO)2(η-PPh2(o-C6H4)C(O)H)2 and its reaction with C60

Reaction of Mo(CO)₃(NCMe)₃ and PPh₂(o-C₆H₄)C(O)H (abbreviated as PCHO) at room temperature affords Mo(CO)₂(η³-PCHO)₂ (1), while compound 1 and the phosphine-imine complex Mo(CO)₄(η²-PPh₂(o-C₆H₄)CHNMe) (2) are obtained by using Mo(CO)₃(η³-(MeNCH₂)₃) as the reactant. Thermal reaction of 1 with C₆₀ products Mo(CO)₂(η⁴-(PPh₂(o-C₆H₄)CH)₂)(η²-C₆₀) (3) in low yield, apparently through coupling of the formyl moieties. The structures of 1 and 3 have been determined by an X-ray diffraction study. The two aldehyde groups of 1 and C₆₀ ligand of 3 are coordinated to the molybdenum atom in a π-fashion.     

Formation of the silylene-bridged complex Fe2(CO)6(μ2-SiCl2)3 from cis-Fe(CO)4(SiCl3)2: an experimental and computational study

Abstract  

Thermolysis of cis-Fe(CO)₄(SiCl₃)₂ results in the formation of the novel compound Fe₂(CO)₆(μ₂-SiCl₂)₃, which was characterized by single crystal X-ray diffraction. Density functional theory calculations were carried out to elucidate possible reaction steps leading to the formation of Fe₂(CO)₆(SiCl₂)₃, including CO dissociation and chlorine abstraction by a SiCl₃ radical generated from homolytic Fe–Si bond cleavage involving a singlet–triplet intersystem crossing.     

Mixed-ligand complexes [Cd(DMSO)5(NCS)][Cr(NH3)2(NCS)4] · 3DMSO and [Mn(DMSO)4(H2O)2][Cr(NH3)2(NCS)4]2 · 6DMSO · 2H2O: Syntheses and crystal structures

New mixed-ligand coordination compounds[Cd(DMSO)₅(NCS)][Cr(NH₃)₂(NCS)₄] · 3DMSO (I) and [Mn(DMSO)₄(H₂O)₂][Cr(NH₃)₂(NCS)₄]₂ · 6DMSO · 2H₂O (II) have been synthesized and studied by IR spectroscopy and X-ray diffraction analysis. The crystals of compound I are monoclinic, a = 14.5275(7), b = 23.1692(11), c = 14.6969(6) ?, β = 97.057(2)°, V = 4909.4(4) ?³, space group P2₁/c, Z = 4, ρ_calcd = 1.507 g/cm³, R = 0.0556. The crystals of compound II are triclinic, a = 11.7784(3), b = 12.1760(3), c = 13.1922(2) ?, α = 85.5420(10)°, β = 87.9000(10)°, γ = 70.3680(10)°, V = 1776.46(7) ?³, space group P , Z = 1, ρ_calcd = 1.444 g/cm³, R = 0.0350. Original Russian Text ? E.A. Gerasimova, T.V. Utkina, E.V. Peresypkina, A.V. Virovets, T.G. Cherkasova, 2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 5, pp. 751–755.     

[Cu(TO)2(H2O)4](PA)2的合成和晶体结构

[Cu(TO)₂(H₂O)₄](PA)₂ was prepared by mixing the aqueous solution of 1,2,4-triazol-5-one(TO) and Cu(PA)₂. The molecular structure and crystal structure of the title complex was determined by X-ray single crystal diffraction method. The crystal is triclinic, space group with a=0.7321(1)nm,b=0.7474(2)nm,c=1.3649(3)nm;α=88.65(2)°,β=85.63(1)°,γ=63.35(1)°;V=0.6655(2)nm³,Z=1. The Cu²⁺ coordinated with two TO molecule through its 2-nitrogen atom and four water molecules and showed an octahedral configuration.     

Crystal structures of barium bis(iminodiacetato)cobaltates(III): [Ba(H2O)6][Co(Ida)2]2 · H2O and Ba4(H2O)14][Co(Ida)2]5(ClO4)3 · 5.46H2O · 2CH3OH

The structures of the crystals of Ba₄[trans(N)-Co(Ida)₂]₃[cis-(N)-Co(Ida)₂]₂(ClO₄)₃ · 19.46H₂O · 2CH₃OH (I) and Ba[trans-(N)-Co(Ida)₂]₂ · 7H₂O (II) (H₂Ida is iminodiacetic acid) were determin by X-ray diffraction. The crystals of I containing two geometric isomers of the complex anions [Co(Ida)₂]⁻ were obtained by a slow cooling of a hot solution, which contained initially only the cis-isomer. One Ba atom in I interacts with the trans-complex and with two cis-complexes to give a three-dimensional framework in crystal I. The positive charge of the last framework is compensated by one more trans-complex and by the perchlorate ions, one of which acts as a bidentate ligand with respect to the Ba atom. The crystals of II are built of the chains with the alternating Ba atoms and the trans-(N)-[Co(Ida)₂]⁻ anions. The other anions of the same structure are each “suspended” to the Ba atoms of the chain. Original Russian Text ? M. Zabel, A.I. Poznyak, V.I. Pawlowskii, 2008, published in Koordinatsionnaya Khimiya, 2008, Vol. 34, No. 11, pp. 831–836.     

Crystal structure of [Pd(NH3)4]3[Ir(NO2)6]2·H2O

A single crystal of [Pd(NH₃)₄]₃[Ir(NO₂)₆]₂·H₂O double complex salt is studied by X-ray diffraction. Crystallographic characteristics are as follows: a = 21.0335(5) ?, b = 8.0592(2) ?, c = 21.3452(5) ?, β = 91.254(1)°, V = 3617.43(15) ?³, P2₁/c space group, Z = 4, d _x = 2.714 g/cm³. Single-layer pseudohexagonal packing of complex anions is determined along the [−1 0 1] direction in the structure. Complex cations and crystallization water molecules are located between the mentioned layers.     

Unsaturation in binuclear cyclopentadienylchromium carbonyl thiocarbonyls: Viability of (η-C5H5)2Cr2(CS)2(CO)3 in contrast to (η-C5H5)2Cr2(CO)5

The cyclopentadienylchromium carbonyl thiocarbonyls Cp₂Cr₂(CS)₂(CO)_n (n = 4, 3, 2, 1) have been studied by density functional theory using the B3LYP and BP86 functionals. The lowest energy Cp₂Cr₂(CS)₂(CO)₄ structure can be derived from the experimentally characterized unbridged Cp₂Cr₂(CO)₆ structure by replacing the two terminal carbonyl groups furthest from the Cr-Cr bond with two terminal CS groups. The two lowest energy Cp₂Cr₂(CS)₂(CO)₃ structures have a single four-electron donor η²-μ-CS group and a formal Cr-Cr single bond of length ∼3.1 Å. In contrast to the carbonyl analogue Cp₂Cr₂(CO)₅ these Cp₂Cr₂(CS)₂(CO)₃ structures are viable with respect to disproportionation into Cp₂Cr₂(CS)₂(CO)₄ and Cp₂Cr₂(CS)₂(CO)₂ and thus are promising synthetic targets. The lowest energy Cp₂Cr₂(CS)₂(CO)₂ structures have all two-electron donor CO and CS groups and short CrCr distances around ∼2.3 Å suggesting the formal triple bonds required to give the chromium atoms the favored 18-electron configurations. These Cp₂Cr₂(CS)₂(CO)₂ structures are closely related to the known structure for Cp₂Cr₂(CO)₄. In addition, several doubly bridged structures with four-electron donor η²-μ-CS bridges are found for Cp₂Cr₂(CS)₂(CO)₂ at higher energies. The global minimum Cp₂Cr₂(CS)₂(CO) structure is a triply bridged triplet with a CrCr triple bond (2.299 Å by BP86). A higher energy singlet Cp₂Cr₂(CS)₂(CO) structure has a shorter Cr-Cr distance of 2.197 Å (BP86) suggesting the formal quadruple bond required to give each chromium atom the favored 18-electron configuration.     

[Gd2(Gly)6(H2O)4](ClO4)6(H2O)5的合成、晶体结构与热化学研究

利用微波技术合成了配合物[Gd₂(Gly)₆(H₂O)₄](ClO₄)₆(H₂O)₅, 进行了化学成分分析、红外表征和热重分析. 应用X衍射仪测定其晶体结构, 该晶体为一维链结构, 属三斜晶系, P 空间群, 晶胞参数: a＝1.1569(17) nm, b＝1.4138(2) nm, c＝1.5642(2) nm, α＝96.910(2)°, β＝102.735(2)°, γ＝105.512(2)°, V＝2.3606(6) nm³, Z＝2, D_c＝2.144 g•cm^－3. 采用精密溶解-反应量热计, 通过设计热化学循环, 计算出了该配合物的标准摩尔生成焓为 －(7960.73±3.23) kJ•mol^－1.     

Mechanistic studies on the alcoholysis and aminolysis of [(MeZn)2{μ-N(H)tBu}{μ-N(CH2Py)2}]

The reaction of bis(2-pyridylmethyl)amine (II) with t-butylamine and dimethylzinc gives the heteroleptic [(MeZn)₂{μ-N(H)tBu}{μ-N(CH₂Py)₂}] (1). Stoichiometric alcoholysis of 1 with methanol leads to the exchange of the μ-N(H)tBu moiety. Almost quantitatively the corresponding methoxide [(MeZn)₂(μ-OMe){μ-N(CH₂Py)₂}] (2) is formed. Alternatively bis(alkylzinc)methoxide-bis(2-pyridylmethyl)amides (Alkyl = methyl (2), bis(trimethylsilyl)methyl) (3)) are also accessible by direct zincation of bis(2-pyridylmethyl)amine (II) and methanol with dialkylzinc regardless of the bulkiness of the alkyl groups. Extensive DFT calculations on the alcoholysis mechanism reveal the preferential insertion of methanol into a zinc amide bond rather than the cleavage of zinc carbon bonds. An intermediate with a Zn[μ-(MeO?H?NHR)]Zn functionality is predicted. Aminolyis of 1 with t-butylamine leads to intermediates with Zn[μ-(RNH ? H ? NHR)]Zn functionalities, respectively. We were able to detect the latter by ¹H NMR spectroscopy. The aminolysis of 1 with an excess of phenylamine results in a partial decomposition of the complex leading to the hexanuclear amide [{Zn(μ-N(H)Ph)}{MeZn(μ-N(H)Ph)}₂{μ-N(CH₂Py)₂}]₂ (4). Compound 2 is able to cleave silicon grease when dissolved in t-butylamine yielding [(MeZn)₂{μ-N(CH₂Py)₂}₂Zn{μ-(OMe₂Si)₂O}] (5). The X-ray structures of complexes 1-5 are discussed.     

Double complex salts [Pd(NH3)4]3[Rh(NO2)6]2, [Pd(NH3)4]3[Rh(NO2)6]2·H2O as promising precursors to prepare Pd-Rh nanoalloys

Two new double complex salts [Pd(NH₃)₄]₃[Rh(NO₂)₆]₂ (I) and [Pd(NH₃)₄]₃[Rh(NO₂)₆]₂·H₂O (II) are synthesized and characterized. The techniques to produce one-phase residues of the salts are developed. The crystallographic data for I: a = 18.915(2) ?, V = 6767.4 ?³, F-43c space group, Z = 8, d _x = 2.548 g/cm³; II: a = 21.160(6) ?, b = 8.085(7) ?, c = 21.363(4) ?, β = 91.71(4)°, V = 3661.1(6) ?³, P2₁/c space group, d _x = 2.357 g/cm³. Thermal properties of the obtained compounds in the hydrogen and helium atmosphere are studied. It is shown that the final product of their decomposition both in the inert and reducing atmosphere is a powder consisting of bimetallic nanosized particles (nanoalloy) of Pd_0.59Rh_0.41 (Fm-3m space group, a = 3.856(2) ?, crystallite size of 8–11 nm).     

Cu(NO3)2(La(NO3)3)-CO(NH2)2-H2O三元体系的等温溶度研究

本文首次报道三元体系Cu(NO₃)₂-CO(NH₂)₂-H₂O(30℃)和La(NO₃)₃-CO(NH₂)₂-H₂O(25℃)的等温溶度及饱和溶液、折光率,绘制相应的溶度图及折光率-组成图。体系中发现有组成为Cu(NO₃)₂·4CO(NH相似文献   

纳米晶(CeO2)1-x(BiO1.5)x固溶体的水热合成

在240℃水热体系中首次合成出系列纳米晶固溶体(CeO