MOLECULAR STRUCTURE OF DINUCLEAR COBALT COMPLEX WITH CHELATING 1, 3-BIS (DIPHENYLPHOSPHINO ) PROPANE LIGAND

<正> Co2 ( CO ) 6 (dppp ) Cdppp = 1,3-bis ( diphenylphosphino ) propane = Ph2P(CH2)3PPh2D, Mr=698. 38, monoclinic, space group P21/c, a=14. 952(8) , b = 13.44(2), c = 16. 72(1) A. β=110.56(4)°, V=3147(9) A3, Z = 4, A=1. 47 g/cm3, λ(MoXα) = 0. 71069 A, F(000) = 1424, λ(MoKα) = 11. 93 cm-1, R = 0. 032 and Rw = 0. 044 for 4553 observed independent reflections with I>4. 0σ(I). The molecular structure of the complex shows that the dppp ligand chelates one of the two cobalt atoms of the complex molecule, and there are two bridging carbonyl groups between the two cobalt atoms. The Co-Co bond length is 2. 534(3) A . The chelating dppp ligand results in the asymmetrization of the molecule.     

Synthesis and Structure of a Mixed Phosphine-Thiolato Polymer with a Linear Chain Network [Ag2 (μ2-dppe)3 (S-mbo)2]n · 2nDMF [dppe = 1,2-Bis (diphenylphosphino)ethane, mbo= 2-Mercaptobenzoxazole]

Diphosphino organochalcogenide metal complexes have been investigated presently fortheir possible use as anti-cancer agents[1-3]. However, the area of silver complexes withmixed phosphine-thiolato ligands has scarcely been touched[4]. As a heterocyclic thiolato lig-and with potential S and N donors, 2-mercaptobenzoxazole (Hmbo) is interesting because ofthe structural chemistry of its multifunctional coordination modes (unidentate-N, unidentate-S or bidentate-N : S)[5-8]. Until now, Ag-mbo complex has been unknown to our knowl-edge, despite the fact that its complexes of Sn[5] , Au[6] and Li[7,8] have been reported. Hereinwe report the X-ray crystal structure of a self-assembled coordination polymer[Ag2(μ2-dppe)3(S-mbo)2]n · 2nDMF(dppe=1,2-bis(diphenylphosphino)ethane, Hmbo=2-mercaptobenzoxazole, DMF = dimethyl formamide).     

Crystal Structure of Di[bis(diphenylphosphino)propane]Copper(Ⅰ) Perchlorate Complex

1INTRODUCT1oNIthasbeenwellknownthatthereactionofcopper(E)saltswithditertiaryphosphinesorarsinesisoftenaconvenientroutetocopper(I)analogues.8-dimethylarsinoquinolinee,3-methylthiopropyldimethylarsineand(o-diphenylarsi-nophenyl)diphenylphosphinesulphideallonlyyieldcopper(I)complexesofthiskindofligandsfromreactioninvolvingcopper(I)salts.Insimilarmanner,copper(I)nitratecomplexesofstoichiometryCu(dppm)(NO,),Cu2(dppe)3(NO,)2,Cu-(dppe),(NO,),andCu(dppe)(NO,)havebeenprepared.ltappearsthatthe…     

One—dimensional Chain Topology in [Ag（C6H6NCl）2]（ClO4）,Generated through Weak Interaction between Molecules

1 INTRODUCTION It is known that the research of supramolecular chemistry and crystal engineering of coordination compound receives great interest nowadays.[1~6] Supramolecules are not just collection of molecules, generally, the formation of a supramolecule is through hydrogen bonding, π-π stacking interaction and the weak interaction between molecules.[1] Recently, more and more supramolecular compounds containing polymeric Ag(I) species have been described due to the coordination mode…     

Metal Trimethylsilylthiolates for the Synthesis of Trinuclear MnPd2 Complexes

The manganese(II)‐palladium(II)‐sulfide complex [MnCl₂(μ₃‐S)₂Pd₂(dppp)₂] ( 2 ) was prepared from the reaction of [PdCl₂(dppp)] with [Li(N,N'‐tmeda)]₂[Mn(SSiMe₃)₄] ( 2 ) in a 2:1 ratio under mild conditions. The new trimethylsilylthiolate complex [Pd(dppp)(SSiMe₃)₂] ( 3 ) was synthesized from the reaction of [Pd(dppp)(OAc)₂] with two equivalents of Li[SSiMe₃]; this was then used in a reaction with [Mn(CH₃CN)₂(OTf)₂] to form the manganese(II)‐palladium(II)‐sulfide cluster [Mn(OTf)(thf)₂(μ₃‐S)₂Pd₂(dppp)₂]OTf ( 4 ).     

Catalyst-transfer polycondensation. mechanism of Ni-catalyzed chain-growth polymerization leading to well-defined poly(3-hexylthiophene)

We studied the mechanism of the chain-growth polymerization of 2-bromo-5-chloromagnesio-3-hexylthiophene (1) with Ni(dppp)Cl2 [dppp = 1,3-bis(diphenylphosphino)propane], in which head-to-tail poly(3-hexylthiophene) (HT-P3HT) with a low polydispersity is obtained and the M(n) is controlled by the feed ratio of the monomer to the Ni catalyst. Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectra showed that the HT-P3HT uniformly had a hydrogen atom at one end of each molecule and a bromine atom at the other. The reaction of the polymer with aryl Grignard reagent gave HT-P3HT with aryl groups at both ends, which indicates that the H-end was derived from the propagating Ni complex. The degree of polymerization and the absolute molecular weight of the polymer could be evaluated from the 1H NMR spectra of the Ar/Ar-ended HT-P3HT, and it was found that one Ni catalyst molecule forms one polymer chain. Furthermore, by reaction of 1 with 50 mol % Ni(dppp)Cl2, the chain initiator was found to be a bithiophene-Ni complex, formed by a coupling reaction of 1 followed by insertion of the Ni(0) catalyst into the C-Br bond of the dimer. On the basis of these results, we propose that this chain-growth polymerization involves the coupling reaction of 1 with the polymer via the Ni catalyst, which is transferred intramolecularly to the terminal C-Br bond of the elongated molecule. We call this mechanism "catalyst-transfer polycondensation".     

双核银配合物[Ag2(μ-(4-MeC6H4O)2PS2)2(Phen)2]的光谱性质和晶体结构

合成了双核银配合物[Ag2(μ-(4-MeC6H4O)2PS2)2(Phen)2](phen为1,10-邻菲咯啉),用元素分析、红外光谱、紫外-可见光谱和热重分析进行了表征,并用X-射线衍射法测定了晶体结构。该晶体属于正交晶系,Pbca空间群,晶胞参数为:a=1.2035(2)nm,b=1.638 3(3)nm,c=2.517 1(5)nm,V=4.963 1(17)nm 3,Dc=1.599 g.m-3,Z=4,F(000)=2 416,μ(Mo Kα)=1.072 mm-1,S=1.066,(Δ/σ)max=0.001,R1=0.037 6,wR2=0.088 8(I>2σ(I))。晶体结构研究表明每个Ag原子与不同配体(4-MeC6H4O)2PS2-的2个S原子和1个phen配体的2个N原子配位形成了具有椅式构型的八元环Ag2S4P2,Ag原子为畸变四面体AgS2N2构型,配合物通过phen的π-π堆积形成了一维结构,分子间的弱氢键C-H…O和C-H…π作用使分子进一步形成了三维网络结构。     

Ag(Ⅰ) Schiff碱配合物的合成及其晶体结构

本文以2-醛基吡啶和1,2-二(对氨基苯氧基)乙烷进行缩合得到Schiff碱配体L,再分别同AgNO3和AgClO4进行配位反应,得到了2个配合物[Ag2(NO3)2L](1)和{[AgL]ClO4}n(2),并用元素分析,FTIR和X-射线单晶衍射进行了表征。结果表明,配合物1属于单斜晶系,P21/c空间群,Ag(I)的配位环境为平面三角形,配体L同时和2个Ag(Ⅰ)离子配位形成双核配合物。配合物2属于单斜晶系,P21/n空间群,每个Ag(Ⅰ)的配位环境均为扭曲四面体,每个配体L通过其两端的2个氮原子同2个金属离子配位桥联形成一维螺旋链结构。     

Reactions of a gold(I) thiolate complex [Au(Tab)(2)](2)(PF(6))(2) (Tab = 4-(trimethylammonio)benzenethiolate) with diphosphine ligands

Reactions of a gold(i) thiolate complex [Au(Tab)(2)](2)(PF(6))(2) (Tab = 4-(trimethylammonio)benzenethiolate) with equimolar 1,2-bis(diphenylphosphine)ethane (dppe), 1,3-bis-(diphenylphosphine)propane (dppp) or 1,4-bis-(diphenylphosphine)butane (dppb) in MeOH-DMF-CH(2)Cl(2) gave rise to three polymeric complexes [Au(2)(Tab)(2)(dppe)](2)(PF(6))(4)·2MeOH (1·2MeOH), [Au(2)(Tab)(2)(dppp)]Cl(2)·0.5MeOH·4H(2)O (2·0.5MeOH·4H(2)O), and [Au(4)(μ-Tab)(2)(Tab)(2)(dppb)](PF(6))(4)·4DMF (3·4DMF), respectively. Analogous reaction of 1 with dppb in DMF/C(2)H(4)Cl(2) produced one tetranuclear complex [Au(2)(μ-Tab)(Tab)(2)](2)Cl(4)·2DMF·4H(2)O (4·2DMF·4H(2)O). Complexes 1-4 were characterized by elemental analysis, IR spectra, UV-vis spectra, (1)H and (31)P{(1)H} NMR and single crystal X-ray analysis. Compounds 1 and 2 consist of [Au(Tab)](2) dimeric fragments that are bridged by dppe or dppp ligands to form a 1D linear chain extending along the a axis. For 3, each [Au(4)(Tab)(2)(μ-Tab)(2)] fragment is linked by a pair of dppb ligands to afford another 1D chain extending along the c axis. For 4, the four [Au(Tab)](+) fragments are linked by two Au-Au bonds and two doubly bridging Tab ligands to form a {[Au(Tab)](4)(μ-Tab)(2)} chair-like cyclohexane structure. Hydrogen-bonding interactions in 2 and 4 lead to the formation of interesting 2D hydrogen-bonded networks. The luminescent properties of 1-4 in solid state were also investigated.     

Formation of N-heterocyclic diphosphine ligands from Ag(I)-assisted condensation reactions between bdppeda and formaldehyde and their binuclear silver(I) complexes

The reaction of [Ag(MeCN)(4)]ClO(4) with N,N,N',N'-tetra(diphenylphosphanylmethyl)ethylenediamine (dppeda) in CH(2)Cl(2)/MeOH afforded an unexpected cationic binuclear complex [Ag(2)(L(1))(2)(η,η-μ-ClO(4))(2)](ClO(4))(2) (L(1) = N,N'-bis(diphenylphosphanylmethyl)-3H-4,5-dihydroimidazole-1-ium) (1). Compound 1 was also prepared in high yield from reactions of [Ag(MeCN)(4)]ClO(4) with N,N'-bis(diphenylphosphanylmethyl)ethylenediamine (bdppeda) in the presence of formaldehyde (HCHO) or formic acid (HCOOH). Analogous reactions of AgCl with bdppeda and HCHO resulted in the formation a neutral binuclear complex [Ag(2)(L(2))(2)(μ-Cl)(2)] (L(2) = N,N-bis(diphenylphosphanylmethyl)-tetrahydroimidazole) (2). Treatment of 1 with concentrated HCl gave rise to a partially anion-exchanged product [Ag(2)(L(1))(2)(μ-Cl)(2)](ClO(4))(2) (3). Compounds 1 and 3 have a similar cationic binuclear structure, in which a [Ag(2)(η,η-μ-ClO(4))(2)] or [Ag(2)(μ-Cl)(2)] ring is sandwiched by two in situ-formed cationic L(1) ligands. The L(1) ligand may be generated by the Ag(I)-assisted condensation reaction between bdppeda and HCHO or HCOOH. Compound 2 holds a neutral binuclear structure, in which a [Ag(2)(μ-Cl)(2)] ring is connected by two in situ-formed L(2) ligands from its top and bottom sites. The neutral ligand L(2) may be produced from another Ag(I)-assisted condensation reaction between bdppeda and HCHO. The in situ formation of the L(1) and L(2) ligands provides a new route to the N-heterocyclic diphosphine ligands, and an interesting insight into the coordination chemistry of their metal complexes.     

Behavior of neutral phosphido derivatives of platinum and palladium toward silver centers

The reaction of the neutral binuclear complexes [(R(F))(2)Pt(μ-PPh(2))(2)M(phen)] (phen = 1,10-phenanthroline, R(F) = C(6)F(5); M = Pt, 1; M = Pd, 2) with AgClO(4) or [Ag(OClO(3))(PPh(3))] affords the trinuclear complexes [AgPt(2)(μ-PPh(2))(2)(R(F))(2)(phen)(OClO(3))] (7a) or [AgPtM(μ-PPh(2))(2)(R(F))(2)(phen)(PPh(3))][ClO(4)] (M = Pt, 8; M = Pd, 9), which display an "open-book" type structure and two (7a) or one (8, 9) Pt-Ag bonds. The neutral diphosphine complexes [(R(F))(2)Pt(μ-PPh(2))(2)M(P-P)] (P-P = 1,2-bis(diphenylphosphino)methane, dppm, M = Pt, 3; M = Pd, 4; P-P = 1,2-bis(diphenylphosphino)ethane, dppe, M = Pt, 5; M = Pd, 6) react with AgClO(4) or [Ag(OClO(3))(PPh(3))], and the nature of the resulting complexes is dependent on both M and the diphosphine. The dppm Pt-Pt complex 3 reacts with [Ag(OClO(3))(PPh(3))], affording a silver adduct 10 in which the Ag atom interacts with the Pt atoms, while the dppm Pt-Pd complex 4 reacts with [Ag(OClO(3))(PPh(3))], forming a 1:1 mixture of [AgPdPt(μ-PPh(2))(2)(R(F))(2)(OClO(3))(dppm)] (11), in which the silver atom is connected to the Pt-Pd moiety through Pd-(μ-PPh(2))-Ag and Ag-P(k(1)-dppm) interactions, and [AgPdPt(μ-PPh(2))(2)(R(F))(2)(OClO(3))(PPh(3))(2)][ClO(4)] (12). The reaction of complex 4 with AgClO(4) gives the trinuclear derivative 11 as the only product. Complex 11 shows a dynamic process in solution in which the silver atom interacts alternatively with both Pd-μPPh(2) bonds. When P-P is dppe, both complexes 5 and 6 react with AgClO(4) or [Ag(OClO(3))(PPh(3))], forming the saturated complexes [(PPh(2)C(6)F(5))(R(F))Pt(μ-PPh(2))(μ-OH)M(dppe)][ClO(4)] (M = Pt, 13; Pd, 14), which are the result of an oxidation followed by a PPh(2)/C(6)F(5) reductive coupling. Finally, the oxidation of trinuclear derivatives [(R(F))(2)Pt(II)(μ-PPh(2))(2)Pt(II)(μ-PPh(2))(2)Pt(II)L(2)] (L(2) = phen, 15; L = PPh(3), 16) by AgClO(4) results in the formation of the unsaturated 46 VEC complexes [(R(F))(2)Pt(III)(μ-PPh(2))(2)Pt(III)(μ-PPh(2))(2)Pt(II)L(2)][ClO(4)](2) (17 and 18, respectively) which display Pt(III)-Pt(III) bonds.     

Synthesis and Crystal Structure of a One-dimensional Silver(Ⅰ) Coordination Polymer with 4,4'-Bipyridine

The title compound,{[Ag2(bipy)2(H2O2]·pydc·2H2O}n(bipy=4,4'-bipyridine,pydc=pyridine-3,5-dicarboxylate),has been synthesized by the reaction of Ag2O with pydc and bipy in CH3OH solution.It crystallizes in the monoclinic system,space group C2/c with a=21.419(8),b=7.515(3),c=18.070(7)(A),β=108.273(6)°,Mr=765.27,V=2761.9(17)(A)3,Z=4,Dc=1.840 g/cm3,F(000)=1528,μ=1.478 mm-1,the final R=0.0307 and wR=0.0681.The structure determined demonstrated that the Ag(Ⅰ)is three-coordinated by two nitrogen atoms from bipy and one water molecule,forming a one-dimensional coordination polymer[Ag2(bipy)2(H2O)2]n2n ,which is further linked to generate a two-dimensional layer structure via Ag…Ag attractions.     

Organometallic oligomers based on 1,8-Diisocyano-p-menthane (dmb): syntheses and characterization of the [[M(diphos)(dmb)]BF4]n and [[Pd2(diphos)2(dmb)](ClO4)2]n materials (M = Cu, Ag; diphos = dppe, dppp)

A new strategy to synthesize organometallic oligomers is presented and consists of using the title diisocyanide and chelated metal fragments with bis(diphenylphosphine)alkanes. The title materials are synthesized by reacting the [M(dppe)(BF4)] and [M2(dppp)2](BF4)2 complexes (M = Cu, Ag; dppe = bis(diphenylphosphino)ethane, dppp = bis(diphenylphosphino)propane) with dmb and the Pd2-bonded d9-d9 Pd2(dmb)2Cl2 dimer with dppe or dppp. The model compounds [M(diphos)(CN-t-Bu)2]BF4 (M = Cu, Ag) and [Pd2(diphos)2(CN-t-Bu)2](ClO4)2 (diphos = dppe, dppp) have been prepared and characterized as well for comparison purposes. Three of the model compounds were also characterized by X-ray crystallography to establish the diphosphine chelating behavior. The materials are amorphous and have been characterized from the measurements of the intrinsic viscosity, DSC, TGA, and XRD, as well as their capacity for making stand-alone films. The intrinsic viscosity data indicate that the Cu and Pd2 materials are oligomeric in solution (approximately 8-9 units), while the Ag materials are smaller. For [[Cu(dppe)(dmb)]BF4]n, a glass transition is reproducibly observed at about 82 degrees C (DeltaCp = 0.43 J/(g deg)), which suggests that these materials are polymeric in the solid state. The Cu and Ag species are luminescent in the solid state at room temperature exhibiting lambda(max) and tau(e) (emission lifetime) around 480-550 nm and 18-48 micros, respectively, while the Pd2 species are not luminescent under these conditions. During the course of this study, the unsaturated [M2(dppp)2](BF4)2 starting materials (M = Cu, Ag) were prepared, one of which (M = Ag) was characterized by crystallography. The bridging behavior of the dppp ligand in this case contrasts with the chelating behavior seen for the saturated [Cu(dppp)(CN-t-Bu)2]BF4 complex.     

MOLECULAR AND CRYSTAL STRUCTURE OF (μ-HOCH_2 CH_2 S)_2 Fe_2 (CO)_4(PPh_3)_2

<正> The molecular and crystal structure of the complex (μ-HOCH2CH2-S)2 Fe2(CO)4(PPh3)2 synthesized by reaction of ethylene epoxide with (μ-Lis)2Fe2(CO)6, followed by EtOH alcoholysis and PPh3 substitution,was determined by X-ray diffraction technique. The crystals are triclinic,space group P 1,with a= 10. 902(2),b=12. 106 (2),c=16. 123(4) A ,V= 2079. 36A3,α=78. 13(1),β=89. 37(2),γ=87. 93(1)°, Z = 2,Dx=1. 44 g/cm3.μ(MoKa) = 9. 149cm-1, F(000) = 940. The final R and Rw equal to 0. 055 and 0. 068,respectively,for 3598 observed independent reflections. In this molecule two PPh3 ligands are trans to the Fe - Fe bond and axially coordinated to two iron atoms. In addition,two hydroxylethyl groups are attached to bridging sulfur atoms by e-type of bond and thus this molecule is an ee conformer.     

Unusual coordination in a silver thionate complex. Synthesis,structural characterization and theoretical calculations of dinuclear and polynuclear silver(I) thiosaccharinates with pyridine and 1,10-phenanthroline

Treatment of Ag₆(tsac)₆ (tsac = thiosaccharinate anion) with pyridine (py) and 1,10-phenanthroline (o-phen) each affords two novel silver(I)-thiosaccharinate complexes: dinuclear [Ag₂(tsac)₂py] (1) and polynuclear [Ag(tsac)(o-phen)]_n (2). Both crystal structures have been determined by X-ray diffraction and spectroscopic structural analysis (IR and Raman, UV–Vis, ¹H and ¹³C NMR) have also been made for both compounds. Thermal stability analysis (TGA and DTA) of complex 1 are used to confirm the strength of the pyridine coordination to the silver ion. The molecular structure of complex 1 shows some astonishing characteristics. The two silver atoms are in different environments: one of them is surrounded by two S atoms, while the other completes its coordination sphere by three N atoms, two from the thiosaccharinate anions and the third from a pyridine molecule. The short Ag(1)–Ag(2) contact distance, 2.9681(8) Å, indicates an interaction between the two silver metal atoms exists. Complex 2 shows a thiosaccharinate molecule bridging two silver atoms through the exocyclic S atom while the o-phenanthroline ligand is coordinated as a bidentate N,N chelate, forming a polynuclear chain. Quantum chemical calculations confirm the argentophilic character of the Ag–Ag interaction in complex 1, and its structure and vibrational assignments were correlated and confirmed theoretically.     

Hydrothermal Synthesis and Crystal Structure of a Novel Dinuclear Co(Ⅱ) Complex:[Co2(2,2'-bpy)_2(μ-L)_2(L)_2(μ-H_2O)](HL=4-Chlorobenzoic Acid)

A new 4-chlorobenzoic acid bridge Co(Ⅱ) complex [Co2(2,2'-bpy)2(μ-L)2(L)2(μ-H2O)] (HL=4-chlorobenzoic acid) has been obtained by hydrothermal synthesis,and X-ray single-crystal diffraction analysis shows that it crystallizes in the monoclinic system,space group C2/c with a=22.537(5),b=16.212(3),c=15.306(3) ,β=124.37(3)°,V=4616.1(16) 3,Mr=1070.45,Dc=1.540 g/cm3,Z=4,μ=1.012 mm-1,F(000)=2176,the final R=0.0338 and wR=0.0810. The title complex is composed of dinuclear [Co2(2,2'-bpy)2(μ-L)2(L)2(μ-H2O)] molecules. Each Co(Ⅱ) atom is coordinated by two nitrogen atoms from one 2,2'-bipyridine ligand,three oxygen atoms from three 4-chlorobenzoic ions and another oxygen atom from one water molecule. The two Co(Ⅱ) atoms are connected by two 4-chlorobenzoic ions and one bridged water molecule. The dinuclear molecules are interlinked by hydrogen bond and π-π stacking interactions into a three-dimensional supramolecular network.     

Synthesis and Crystal Structure of μ_4－alkyne Cluster Complex（μ_4－η~2－C_2Ph_2）Co_4（CO）_8（μ－CO）_2

ＳｙｎｔｈｅｓｉｓａｎｄＣｒｙｓｔａｌＳｔｒｕｃｔｕｒｅｏｆμ_４－ａｌｋｙｎｅＣｌｕｓｔｅｒＣｏｍｐｌｅｘ（μ_４－η~２－Ｃ_２Ｐｈ_２）Ｃｏ_４（ＣＯ）_８（μ－ＣＯ）_２ＳｏｎｇＬｉ－Ｃｈｅｎｇ;ＳｈｅｎＪｉｎ－Ｙｕ;ＨｕＱｉｎｇ－Ｍｅｉ;Ｈｕａｎｇ...     

Hydrothermal Synthesis and Crystal Structure of a Novel Dinuclear Co(Ⅱ) Complex: [Co2(2,2(')-bpy)2((-L)2(L)2(μ-H2O)] (HL = 4-Chlorobenzoic Acid)

A new 4-chlorobenzoic acid bridge Co(Ⅱ) complex [Co2(2,2(')-bpy)2(μ-L)2(L)2(μ- H2O)] (HL = 4-chlorobenzoic acid) has been obtained by hydrothermal synthesis, and X-ray single-crystal diffraction analysis shows that it crystallizes in the monoclinic system, space group C2/c with a = 22.537(5), b = 16.212(3),c = 15.306(3)(A), β= 124.37(3)°, V = 4616.1(16) (A)3, Mr = 1070.45, Dc = 1.540 g/cm3, Z = 4, μ = 1.012 mm-1, F(000) = 2176, the final R = 0.0338 and Wr = 0.0810. The title complex is composed of dinuclear [Co2(2,2(')-bpy)2(μ-L)2(L)2(μ-H2O)] molecules. Each Co(Ⅱ) atom is coordinated by two nitrogen atoms from one 2,2'-bipyridine ligand, three oxygen atoms from three 4-chlorobenzoic ions and another oxygen atom from one water molecule. The two Co(Ⅱ) atoms are connected by two 4-chlorobenzoic ions and one bridged water molecule. The dinuclear molecules are interlinked by hydrogen bond and π-π stacking interactions into a three-dimensional supramolecular network.     

Preparation and crystal structures of an ionic triple-hydrogen-bridged derivative of 9-BBN hydroborate zirconium(IV)

An ionic dinuclear triple-hydrogen-bridged 9-BBN hydroborate zirconium complex, [K(Et₂O)₄][{(μ-H)₂BC₈H₁₄}₃Zr(μ-H)₃Zr{(μ-H)₂BC₈H₁₄}₃] (1) was formed from the reaction of Zr{(μ-H)₂BC₈H₁₄}₄ with KH and aniline in diethyl ether. The molecular structure of compound 1 was determined by single-crystal X-ray diffraction analysis. Six 9-BBN hydroborate ligands are coordinated to two Zr atoms via two bridging H atoms, and two Zr atoms are connected by three bridging hydrogens in the anion part of this molecule. The distance of Zr?Zr is 3.1025(5) Å. The crystal structure of 1 suggests that agostic interactions between the zirconium metal center and α-C-H of the 9-BBN hydroborate ligand exist in the solid state. The Zr?H distances corresponding to the α-C-H?Zr agostic interactions are 2.579(4) Å and 2.743(4) Å.     

Synthesis, Crystal Structure and Catalytic Behavior of 1-Ethyl-3-benyl-imidazolyl Tetranuclear N-Heterocyclic Carbene Silver Bromide

The title complex [Ag(carbene)2]2[Ag2Br4] has been synthesized by the reaction of Ag2O with 1-ethyl-3-benyl-imidazolium bromide in DMSO at room temperature, and characterized by elemental analysis, 1H NMR and single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group P with a = 10.1597(10), b =11.0646(11), c = 13.0245(14) , α = 102.230(2), β = 90.606, γ = 113.9250(10)o, V = 1300.3(2) 3, Mr = 748.06, Z = 2, Dc = 1.911 g/cm3, μ(MoKα) = 4.60 mm-1 and F(000) = 728. The structure was refined to R = 0.0316 and wR = 0.0835 for 3744 observed reflections with I > 2σ(I). The title compound crystallizes as a centrosymmetric tetranuclear compound. One half of the molecule comprises the asymmetric unit of the structure. The Ag(1) atom is nearly linear or T-shaped when the Ag(1)-Ag(2) interaction is taken into consideration, which is bi-coordinated by two carbene carbon atoms. The Ag(2) atom adopts tetrahedral geometry. The catalytic behavior of the title complex has been investigated, and the results indicate it has a highly catalytic activation for L-lactide polymerization.