Bis-(tetraethylammonium)[tetraazidocuprate(II)] and catena-di-μ-1,1-azido-[di-μ-1,1-azido-bis-(2,4-dimethylpyridine)dicopper(II)]

Two new copper(II) azido complexes, namely bis-(tetraethylammonium)[tetraazidocuprate(II)] (1) and catena-di--1,1-azido-[di--1,1-azido-bis-(2,4-dimethylpyridine)dicopper(II)] (2), have been prepared and characterized by spectroscopic and crystallographic methods. Complex (1) consists of isolated NEt⁺ ₄ cations and [Cu(N₃)₄]^2– anions. The site symmetry around the copper atom in the anion is 4/m. Complex (2) features a 1 D chain structure, five coordinated square pyramidal copper(II) atoms with both azides functioning as -1,1-bridges. The i.r. spectra reveal that both complexes contain asymmetric azido ligands. The solid and solution electronic spectra of (1) and (2) show very strong absorption bands in the visible region associated with N^– ₃ Cu^II charge-transfer transitions. The e.p.r. spectra of powder samples and solutions at room temperature were recorded and discussed.     

Crystal structure of di-μ-amido-bis[diammineplatinum(II)] nitrate

Di-μ-amido-bis[diammineplatinum(II)] nitrate (1) was synthesized as a byproduct during preparation of tetraammineplatinum(II) nitrate. One possible pathway to produce 1 is that [(H₃N)₂Pt(μ- OH)₂Pt(NH₃)₂](NO₃)₂, a well-known complex forming on treatment of cis-Pt(NH₃)₂I₂ with AgNO₃, reacts with aqueous ammonia. The other possible pathway involves deprotonation of [Pt(NH₃)₄](NO₃)₂ to form monomeric Pt(NH₃)₃(NH₂)NO₃ followed by elimination of NH3. Crystals of 1 (from water) are monoclinic (C2/c) with a = 16.834(2) Å, b = 10.573(1) Å, c = 7.415(1) Å, β = 114.846(1)°, and Z = 4. The cationic portion consists of two symmetrical square-planar Pt centers with the inversion center at the midpoint of the Pt(1)???Pt(1A) vector. The Pt(II) ion is coordinated by four N atoms from two ammonia molecules and two bridging amido groups affording a slightly distorted square. The molecules are stacked in such a way that the planes of coordination squares turn out to be parallel to each other with a distance of 3.501 Å. Intermolecular Pt–H interaction between the μ-NH₂ hydrogens and the platinum(II) centers of the adjacent molecule are observed.     

Novel di-μ-chloro-bis[chloro(4,7-dimethyl-1,10-phenanthroline)cadmium(II)] dimer complex: synthesis, spectral, thermal, and crystal structure studies

A novel di-μ-chloro-bis[chloro(4,7-dimethyl-1,10-phenanthroline)cadmium(II)] dimer complex has been prepared by reacting CdCl₂·2.5H₂O with 4,7-dimethyl-1,10-phenanthroline (dmphen) ligand. The complex was characterized on the basis of elemental analysis, FAB-MS, IR, UV–visible, ¹H, and ¹³C NMR spectroscopy, TG/DTA, and X-ray single-crystal diffraction studies. The Cd(II) ions in [CdCl₂(C₁₄H₁₂N₂)]₂ are coordinated to three Cl atoms with the centrosymmetric dimer bridged through the Cl atoms and two N atoms in a slightly distorted square-pyramidal disposition. Several hydrogen bonds formed between the terminal Cl atoms and H-Me/H-Ph groups may stabilize the structure in the dimer form.     

The crystal and molecular structures of di-μ-hydroxy-bis(di-2-pyridylamine)dinitratodicopper(II) and aqua-μ-formato-triformato-bis(di-2-pyridylamine)dicopper(II) monohydrate

The preparation, magnetic and spectroscopic properties, crystal and molecular structures of binuclear complexes of formulae [Cu₂(dpyam)₂(OH)₂(ONO₂)₂] (I), [Cu₂(dpyam)₂(O₂CH)₄(OH₂)].H₂O (II) are described. (I) consists of pairs of copper atoms linked by two hydroxo bridges. The co-ordination geometry at each copper atom is distorted square-pyramidal, the basal plane consisting of two hydroxo oxygen atoms and two nitrogen atoms from a dpyam ligand, while the axial co-ordination sites are occupied by nitrate oxygen atoms. The copper(II) ions in (II) are also in a distorted square-pyramidal environment. They are bridged by a formate group in an anti–syn configuration from a basal position to an axial position, while another axial position is occupied by the water oxygen atom. From magnetic susceptibility measurements at room temperature, both complexes are found to exhibit antiferromagnetic interactions and some magneto-structural trends are discussed.     

The twisted skeleton of 1,9-diaminononane incatena-[catena-,μ-(1,9-diaminononane)cadmium(II) tetra-μ -cyanonickelate(II)]-o-xylene(2/1)

The Hofmann-danon-typeo-xylene clathrate Cd[NH₂(CH₂)₉NH₂]Ni(CN)₄·0.5(CH₃)₂C₆H₄, crystallizes in the triclinic space groupP witha = 15.118(3),b = 14.048(4),c = 7.325(1) Å, = 91.50(2), = 131.66(3), and = 107.50(2)°,V = 1051(1) ų andZ = 2. The structure, refined toR = 0.047 using 2851 reflections, reveals a three-dimensional host framework built of the layers of a two-dimensionalcatena-[cadmium tetra--cyanonickelate(Il)] network and of the ambidentate 1,9-diaminononane (danon) bridging the Cd atoms in adjacent networks. The guesto-xylene molecule is accommodated in the cavity formed in the interlayer space similar to that in the Hofmann-daotn-type. The skeleton of the danon in the Cd-NC₉N-Cd linkage takes a (gauche)₂(trans)₈ conformation twisted at the (gauche)₂ part in contrast with the all-trans conformation of 1,8-diaminononane in the Hofmann-daotn-type clathrate. The twisted (gauche)₂ part of the danon skeleton occupies the interlayer space to such an extent that void space available for the guest o-xylene molecule decreases to half that in the Hofmann-daotn-type clathrate Cd[NH₂(CH₂)₈NH₂]Ni(CN)₄·G.The Crystal structures of ,-Diaminoalkanecadmium(II)Tetracyanonickelate(II) - Aromatic Molecule Inclusion Compounds. VI.     

Synthesis and Crystal Structure of Dibromo [1,1′- bis(diphenylphosphino)ferrocene]cadmium(II)

1 INTRODUCTION The transition metal complexes containing ferrocene ligand arouse the interest of chemists because of their novel structures and special properties[1]. The ferrocene derivatives have been used in electrochemistry, in nonlinear optics, and as molecular ferromagnets. Some complexes of 1,1′-bis(diphenylphosphino)ferrocene (dppf) have been synthesized, and many of their crystal structures have been reported by far[2~5]. Here we report the synthesis and crystal structure of a …     

Synthesis, characterization and crystal structure of tetranuclear copper(II) complex [Cu4(μ-Salophen)2(μ1,1-N3)2(N3)2] with alternating μ1,1-azido and phenoxo bridges

Tetranuclear copper(II) complex [Cu₄(??-Salophen)₂(??_1,1-N₃)₂(N₃)₂] (I) has been synthesized from the reaction of Cu(NO₃)₂ · 3H₂O with the Schiff-base ligand salophen condensed from salicylaldehyde and 1,2-phenylenediamine at the presence of a large excess of NaN₃, which has been characterized by elemental analyses, FT-IR spectroscopy, and single-crystal X-ray diffraction. X-ray diffraction studies show that I is a tetranuclear Cu(II) complex with a pair of end-on (EO) azido ions bridging the copper(II) ions in a central Cu(??_1,1-N₃)₂Cu core and one phenoxo bridging the copper(II) ions in a Cu(??-Salophen)Cu core. All copper(II) ions in I are four coordinated and adopt approximate square planar coordination geometry.     

Poly[cadmium(II)-μ-4,4′-oxydianiline-N:N′-di-μ-thiocyanato-N:S]

The title polymeric complex, [Cd(SCN)₂(C₁₂H₁₂N₂O)], exhibits a three-dimensional framework in which each Cd^II atom is bridged by two η-1,3-(SCN)⁻ groups, forming a double-stranded chain. The unique Cd^II atom lies on an inversion centre and the coordination sphere is completed by two terminal N atoms from two different 4,4′-oxy­dianiline (4,4′-Oda) ligands, furnishing a CdS₂N₄ octahedral geometry. Adjacent polymeric double-stranded chains are linked via the 4,4′-Oda ligands, which lie across twofold rotation axes.     

Crystal structure and spectroscopic study of di-μ(1,1)-azido-di-μ(0,0-nitrato)tetrakis(3,5-lutidine)dicopper(II), [Cu(N3) (NO3) (3,5-lutidine)2]2

A mixed ligand 12 complex of copper(II) azide with 3,5-lutidine, namely di-(1,1)-azido-di(0,0)-nitrato)tetrakis(3,5-lutidine)dicopper(II) has been prepared and characterized by X-ray crystallographic and spectroscopic methods. The dimeric molecule, which possesses a crystallographic inversion center, contains two(1,1) bridging azido ligands. Each copper(II) atom in the cyclic Cu₂N₂ unit is further coordinated by two oxygen atoms from two(0,0-nitrato) bridges at Cu-O distances of 2.465(3) and 2.568(3) Å and two nitrogen atoms from the lutidine molecules [Cu-N=2.003(3) and 2.012(3) Å] to give a distorted tetragonal bipyramid. Both azido ligands are linear [N-N-N angle=179.0(4) and asymmetric N-N=1.207(4) and N-N=1.135(5) Å]. The azido bridges produce a rather short Cu Cu distance of 3.013(2) Å. Infrared and electronic data are presented and discussed.     

Synthesis and Structure of Catena-[Bis(2-Methylimidazole)(μ-Phthalato)cobaltate(II)]

A new coordination compound [Co(Pht)(2-MeIm)₂] (I), where Pht^2–is the deprotonated radical of o-phthalic acid (H₂Pht) and 2-MeIm is 2-methylimidazole, was synthesized. Its structure was established using X-ray diffraction analysis. The crystal is orthorhombic: space group Pca2₁, a= 15.350(3), b= 7.957(2), c= 13.997(3) Å, (calcd.) = 1.505 g/cm³, and Z= 4. The tetrahedral coordination of the Co(II) atom includes two N atoms of two 2-methylimidazole molecules and two oxygen atoms of two carboxyl groups from different acid radicals. The Co–N distances are equal to 2.022(2) and 2.031(2) Å, while the Co–O distances are 1.972(2) and 2.000(2) Å. The carboxyl groups of the Pht^2–radical and the aromatic nucleus form angles of 47.2° and 35.9°, whereas the angle formed by the carboxyl groups themselves is 50.3°. Compound Iis a polymer, which is confirmed by the 1,6-bridging function of the o-phthalic acid radical. The Co···Co distance in a chain is equal to 7.367 Å. Separate chains are united in the crystal into a framework via N–H···O hydrogen bonds.     

Synthesis and Structure of bis(μ-2-aminopyridine N-oxide)-bis[dichlorocopper(II)]

1 INTRODUCTIONMany complexes of 2-aminopyridine N-oxide (apo) have been characterized by infrared spectra, X-ray powder diffraction spectra, and by magnetic measurements and electronic spectra at liquid nitrogen temperature, but very few of them are their crystal X-ray studies[1~3]. Recently, a number of bridged binuclear copper (II) complexes have been reported, some of which have important potential applications in bioinorganic chemistry and materials[4~6]. Particularly, the complexes …     

Structure and properties of di-μ-acetato-dichlorobis(2,2′-bipyridine)dirhodium(II)-trihydrate

Reduction of [Rh₂(-OAc)₂(bpy)₂(H₂O)₂](OAc)₂ and [Rh₂Cl₂(-OAc)₂(bpy)₂] · 3H₂O complexes with ethanol and [Cr₂(OAc)₄(H₂O)₂] has been investigated using e.p.r. and u.v.–vis. spectra. The results indicate that stable complexes containing the [Rh₂ ³⁺] entity are not formed. The X-ray structure of [Rh₂Cl₂(-OAc)₂(bpy)₂] · 3H₂O has been determined. Coordination around the Rh atom is in the form of a distorted octahedron. The complex shows an almost ideal eclipsed conformation. The equatorial coordination sites are occupied by bridging carboxylato ligands and 2,2-bipyridine and axial positions by the Cl ligand and the rhodium atom. The Rh–Rh distance is 2.574 Å.     

Metal-phosphine chalcogenide interactions. Crystal and molecular structures of [di-μ-iodo-bis{(methyl cyanide-N)(triphenylthiophosphorane-S)copper(I)}] and [di-μ-chloro-bis{μ-1,2-ethylenebis(diphenylphosphine selenide-Se,Se)} dicopper(I)]

Complexes of Cu^I with tertiary phosphine chalcogenides are described. CuI reacts with Ph₃PS in MeCN/CH₂Cl₂ to form {CuI(Ph₃PS)(MeCN)} and CuCl reacts with 1,2-ethylene-bis(tertiary phosphine selenide) {dpeSe₂} in MeCN to yield {CuCl(dpeSe₂)}. Both compounds exist as halogen-bridged centrosymmetric dimers: [Cu₂(-I)₂-(Ph₃PS)₂(MeCN)₂] (1) and [Cu₂(-Cl)₂(dpeSe₂)₂] (2) respectively. Compound (1) has almost symmetric Cu—I bonds, d(Cu—I) = 2.6503(8) Å and d(Cu—I) = 2.7196(9) Å, and each Cu is further bonded to a S atom [d(Cu—S) = 2.3444(13) Å] from Ph₃PS and to a N atom [d(Cu—N) = 2.030(5) Å] from MeCN. Compound (2) has unequal Cu—Cl bonds, 2.6390(19) and 2.2806(18) Å and nearly equal Cu—Se bonds [2.4042(11) and 2.4060(11) Å]. The geometry about each Cu center in both cases is distorted tetrahedral. The Cu—Cu bond distance in (2) is 3.249(2) Å as compared with 3.4141(16) Å in (1). MeCN is bonded strongly to Cu^I as the excess of Ph₃PS failed to remove it from the coordination sphere. Compound (2) represents the first structurally characterised example of copper(I) with a bis(tertiary phosphine selenide) (dpeSe₂) acting as a bridging ligand.     

Two 2-D copper(II) azido compounds: catena -poly[ di -μ1,1- azido,di -μN,O-(quinolinecarboxylato)(aqua)copper(II)] and 1-D catena -poly[ di -μN,N′-(quinoxaline)copper(II)nitrate]

We synthesized three copper(II) complexes with two structurally related polydentate ligands, quinoline-4-carboxylic acid (quCOOH) and quinoxaline (qux). The structures of these complexes were determined using X-ray single crystal crystallography. Complex 1, [Cu(quCOO)(N₃)(H₂O)] _n , has a 2-D polymeric structure through di-μ_1,1 azido groups forming (Cu₂N₂) dimeric units and di-μ_N,O quinoline carboxylate bridging the binuclear copper units. [Cu(quCOO)(N₃)(H₂O)] _n · 0.87MeOH, (2), has the same structure as 1 in addition to MeOH molecules separating the 2-D sheets of [Cu(quCOO)(N₃)(H₂O)] _n . [Cu(qux)(NO₃)₂] _n , (3), has no coordinated azido groups, but the quinoxaline is a bidentate bridging ligand giving a 1-D chain, while the μ_O,O′ chelating nitrato groups stabilize the chain structure by forming a square planar coordination sphere around copper. IR and UV–Vis spectra of the complexes are in agreement with the crystal structures.     

Structure of the catena-bis(trimethylamine)cadmium(II)-tetra-μ-cyanonickelate(II) complex and contact self-stabilization of molecules

The [Cd(N(CH₃)₃)₂Ni(CN)₄] complex crystallizes in a tetragonal system, space group 14/mmm with two formula units per unit cell (XRD, Rigaku AFC-6A diffractometer, λ MoK_α, ω/2θ scan mode, θ_max = 38?, 635 observed unique reflections, 53 parameters, R = 0.027). The structure consists of parallel polymer layers made up of coordinated metal atoms and bridging cyanides. The octahedral environment of Cd(II) involves six nitrogen atoms of the four cyanide groups in the layer plane (2.323(4) Å) and the two trimethylamine ligands in the transposition (2.42(1) Å). The square-planar environment of Ni(II) consists of four carbon atoms of the cyanide ligands (1.857(3) Å). The layers are packed according to van der Waals type; the “hollows” near the nickel atoms are filled by the “hills” of the trimethylamino groups from the neighboring layer (the interlayer distance is 7 Å). The spatial complementarity of the layers leads to close packing of the complex and explains the lack of a clathrate-forming ability in the latter. The trimethylamine ligands here play the same role as guest molecules in Hofmann clathrates, stabilizing the planar polymer structure of the complex. This phenomenon is called contact self-stabilization.

     

Crystal structures ofcatena-[diligatocadmium(II) tetra-μ-cyanocadmate(II)] host clathrates: Diamminecadmium(II) tetracyanocadmate(II)-benzene(1/2), diamminecadmium(II) tetracyanocadmate(II)-aniline(1/2), ethylenediaminecadmium(II) tetracyanocadmate(II)-aniline(1/2), and a novel type bis(aniline)cadmium(II) tetracyanocadmate(II)-aniline(2/1)

The crystal structures of the four title clathrate compounds Cd(NH₃)₂Cd(CN)₄ · 2C₆H₆,I, Cd(NH₃)₂Cd(CN)₄ · 2C₆H₅NH₂,II, Cd(NH₂CH₂CH₂NH₂)Cd(CN)₄ · 2 C₆H₅NH₂,III, and Cd(C₆H₅NH₂)₂Cd(CN)₄ · 0.5C₆H₅NH₂,IV, have been analyzed by single crystal X-ray diffraction methods. CompoundI crystallizes in the monoclinic space groupC2/c,a = 12.063(2),b = 12.174(2),c = 14.621(1) Å,β = 90.976(9)°,Z = 4,R = 0.042 for 2388 reflections;II: monoclinic C₂/c,a = 12.1951(9),b = 12.078(1),c = 14.6921(7) Å,β = 93.436(5)°,Z = 4,R = 0.039 for 2374 reflections;III: monoclinicCc,a = 11.027(1),b = 12.0767(9),c = 15.837(1) Å,β = 92.059(9)°,Z = 4,R = 0.041 for 2883 reflections; andIV: monoclinicP2₁/n,a = 15.169(2),b = 16.019(2),c = 8.866(1) Å,β = 95.73(1)°,Z = 4,R = 0.052 for 3612 reflections. The three-dimensionalcatena-[diamminecadmium(II) tetra-μ-cyanocadmate(II)] hosts ofI andII are substantially isostructural to that of the already known Hofmann-Td-type Cd(NH₃)₂Hg(CN)₄ · 2C₆H₆. The three-dimensional en-Td-typecatena-[catena-μ-ethylenediaminecadmium(II) tetra-μ-cyanocadmate(II)] host ofIII, reinforced by the catena-μ-en linking between the octahedral Cd atoms, accommodates the aniline as the guest with a monoclinic distortion from the tetragonal symmetry of the previously reported en-Td-type benzene clathrate. InIV dual behavior of aniline, one as the unidentate ligand in the three-dimensional host and the other as the guest in the cage-like cavity, has been demonstrated.     

DI-μ-CHLORO-BIS[l,2-BIS(DIPHENYLPHOSPHINO)-ETHANEPALLADIUM(II)]: SYNTHESIS AND CRYSTAL STRUCTURE

Abstract

On reacting 1,2-bis(diphenylphosphino)ethanedichloropalladium(II) with equimolar amount of silver perchlorate, a binuclear complex, di-μ-chloro-bis[1,2-bis(diphenylphosphino)ethane-palladium(II)] (1) is formed. The crystal structure of 1 has been solved. It crystallizes with two chloroform molecules. Chloro bridges are symmetrical and normal (Pd-Cl～2.414(3) Å). The immediate environment around palladium is slightly distorted square planar and the P-Pd-P angle is ～85°. IR bands at 290 and 270cm^?1 are observed for the chloro-bridged core of the complex.     

Synthesis and crystal structure of octaaqua(di-μ-bromo)dimanganese(II) dibromide 18-crown-6

A new crystalline complex octaaqua(di-μ-bromo)dimanganese(II) dibromide 18-crown-6, [Mn₂Br₂(H₂O)₈]Br₂ · 18C6, is synthesized and studied by X-ray diffraction analysis. The crystals of compound I are triclinic, space group $P\bar 1$ , a = 9.093 Å, b = 9.683, Å, c = 10.032 Å, α = 111.35°, β = 116.23°, γ = 92.64°, Z = 1. The structure is solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.028 for 3276 independent reflections (CAD4 automated diffractometer, λMoK _α radiation). The [Mn₂Br₂(H₂O)₈]²⁺ complex cation lying at the inversion center is binuclear with two bridging Br atoms and eight water molecules. The coordination polyhedron of one Mn²⁺ cation is a distorted cis-octahedron with two Br atoms and four O atoms of the water molecules at its corners. The centrosymmetric 18C6 molecule has an usual conformation. A crystal of compound I contains a developed three-dimensional network of intermolecular (interionic) hydrogen bonds.     

Attack of cadmium(II) and palladium(II) on cis-(R,S)-[Pd(egta)]2−: coordination rearrangements facilitated by pendant carboxylates

Cd(H2O)2+6–8 reacts with cis-(R, S)-[Pd(egta)]2– producing equimolar amounts of [Cd(egta)]2– and [Pd2(egta)Cl2]2–. The progress of the reaction and products have been followed by recording 1H- and 13C-n.m.r spectra as a function of time. The PdII released in forming [Cd(egta)]2– is thousands of times more reactive than CdII, and intercepts another [Pd(egta)]2– to form the 2:1 complex [Pd2(egta)Cl2]2–; the 2:1 complex is not attacked by CdII. The role of pendant carboxylates below the PdN2O2 plane of cis-(R, S)-[Pd(egta)]2– in supplying a site for docking of an incoming CdII or PdII centre, and in leading the metal near the lone pair of rupturing Pd–N bond of [Pd(egta)]2–, or simply by increasing the residence time of CdII or PdII nearby to accelerate the number of collisions between the ruptured N-base and external metal ions, is described. Although mixed-metal [Cd(Pd)(egta)] intermediates are required for the reaction, no such species achieves a detectably large enough concentration to be seen by 1H-n.m.r. The observed spectra are the sum of the reactant, [Pd(egta)]2–, and products, [Cd(egta)]2– and [Pd2(egta)Cl2]2–, throughout the time-dependent change.