Ag(I) and Cu(II) discrete and polymeric complexes based on single- and double-armed oxadiazole-bridging organic clips

Four new oxadiazole-bridging ligands (L1-L4) were designed and synthesized by the reaction of 2,5-bis(2-hydroxyphenyl)-1,3,4-oxadiazole with isonicotinoyl chloride and nicotinoyl chloride, respectively. L1 and L3 are unsymmetric single-armed ligands (4- or 3-pyridinecarboxylate arm), and L2 and L4 are symmetric double-armed ligands (4- or 3-pyridinecarboxylate arms). Nine new complexes, [Ag(L1)]PF6.CH3OH (1), [Ag(L1)]ClO4.CH3OH (2), Cu(L2)(NO3)2.2(CH2Cl2) (3), [Cu(L2)2](ClO4)2.2(CH2CCl2) (4), Cu(L2)Cl2 (5), [Cu4(L3)2(H2O)2](L3)4(ClO4)4 (6), [Ag(L4)(C2H5OH)]ClO4 (7), [Ag(L4)(C2H5OH)]BF4 (8), and [Ag(L4)(CH3OH)]SO3CF3 (9), were isolated from the solution reactions based on these four new ligands, respectively. L1, L2, and L3 act as convergent ligands and bind metal ions into discrete molecular complexes. In contrast, L4 exhibits a divergent spacer to link metal ions into one-dimensional coordination polymers. New coordination compounds were fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. In addition, the luminescent and electrical conductive properties of these new compounds were investigated.     

Synthesis, crystal structure, and characterization of new tetranuclear Ag(I) complexes with triazole bridges

The self-assembly of Ag(I) ions with 3,5-dimethyl-4-amino-1,2,4-triazole (L1) and 4-salicylideneamino-1,2,4-triazole (L2) gave two novel complexes, [Ag4(mu2-L1)6][Ag4(mu2-L1)6(CH3CN)2](ClO4)8.2H2O (1) and [Ag4(mu2-L2)6(CH3CN)2](AsF6)4.2H2O (2), both of which contain tetranuclearic clusters constructed via Ag(I) ions and six N1,N2-bridged triazoles with a Ag4N12 core. When 4-(6-amino-2-pyridyl)-1,2,4-triazole (L3) was employed, {[Ag4(mu2-L3)4(mu3-L3)2](CF3SO3)4.H2O}n (3), {[Ag4(mu2-L3)4(mu3-L3)2](ClO4)4}n (4), and {[Ag4(mu2-L3)2(mu3-L3)4](PF6)4.CH3CN.0.75H2O}n (5) were isolated. 3 and 4 are 1D polymers, while 5 is a 2D polymer. 1D and 2D coordination polymers are constructed via the self-assembly of Ag4N12 cores as secondary building units (SBUs). The connection of these SBUs can be represented as a ladderlike structure for 1D polymers and a 4.8(2) net for 2D polymers. Electrospray ionization mass spectrometry measurements and NMR (1H and 13C) studies demonstrate that the tetranuclear SBU retains its integrity and the coordination polymers decompose into the tetranuclear Ag4N12 core in solution. 2 exhibits blue emission in the solid state and green emission in solution at ambient temperature. Strong blue fluorescence for complexes 3-5 in the solid state can be assigned to the intraligand fluorescent emission.     

The stepwise formation of mixed-metal coordination networks using complexes of 3-cyanoacetylacetonate

The complexes [Cu(L(1))2] 1, [Fe(L(1))3] 3 and [Al(L(1))3] 4 [L(1) = CH(3)C(O)C(CN)C(O)CH(3)] have been prepared for use as metallo-ligands in mixed-metal coordination networks. Surprisingly, the nature of the copper precursor is important in the synthesis of 1, with the reaction between Cu(NO3)2.3H2O, HL(1) and NEt3 giving [Cu6(micro(3)-OMe)4(micro-OMe)2(L(1))6] 2 instead of the anticipated 1, which was obtained with CuCl2.2H2O under the same conditions. Compound 1 reacts with AgNO3 to form [Cu(L(1))2.AgNO3](infinity) 5, the structure of which contains one-dimensional chains in which Ag+ ions bridge between molecules of 1. These chains are cross-linked into ladders by bridging nitrates. The product obtained from the reaction of 3 and AgNO3 is crucially dependent on the solvent used. The reaction in methanol-acetone gives [Fe(L(1))3.AgNO3](infinity) 6, {[Fe2(micro-OMe)2(L(1))4.2AgNO3].CH(3)C(O)CH(3)}(infinity) 7 and [Fe2(micro-OMe)2(L(1))4.AgNO3](infinity) 8. Compounds 6 and 8 both have one-dimensional chain structures, whereas 7 has a two-dimensional layer structure. The reaction in methanol gives 6 and 8 as the major products and, in addition, small quantities of {[AgFe2(micro-OMe)2(L(1))4]OH.0.4H2O](infinity) 9. Compound 9 has a three-dimensional structure based on doubly interpenetrated PtS nets. Compounds 7-9 contain Fe2(micro-OMe)2(L(1))4 dimers, but the coordination properties of the dimers differ, with all the cyanides coordinated in 7 and 9 but one uncoordinated in 8. The orientation of the cyanide groups depends on the relative chirality of the iron centres. A transmetallation reaction occurs between 4 and AgNO3 to give [Ag(L(1))](infinity) 10, which has a two-dimensional layer structure. Compounds 2, 3 and 5-10 have been characterised by X-ray crystallography.     

Formation of mono-, bi-, tri-, and tetranuclear Ag(I) complexes of C3-symmetric tripodal benzimidazole ligands

The C3-symmetric tripodal ligand tris(2-benzimidazolylmethyl)amine (ntb) and its alkyl-substituted derivatives tris(N-R-benzimidazol-2-ylmethyl)amine (R = methyl, Mentb; R = ethyl, Etntb; R = propyl, Prntb) react with various silver(I) salts to afford mononuclear [Ag(Prntb)(CF3SO3)].0.25H2O, 1, binuclear [Ag2(Mentb)2](CF3SO3)2.H2O, 2, trinuclear [Ag3(Etntb)2](ClO4)3.CH3OH, 3, and tetranuclear [Ag4(ntb)2(CH3CN)2(CF3CO2)2](CF3CO2)2.2H2O, 4. All four complexes have been characterized by elemental analyses, IR spectroscopy, and X-ray crystallography. The Ag(I) ion in 1 is coordinated to the three imine nitrogen atoms of the Prntb ligand and one oxygen atom of the trifluoromethanesulfonate anion in a distorted tetrahedral environment. Dinuclear 2 has C2 symmetry with each Ag(I) atom trigonally coordinated by two arms of one Mentb and one arm of another. Trinuclear 3 has C3 symmetry with a Ag3 regular triangle sandwiched between a pair of Etntb ligands such that one arm of each ligand is involved in linear coordination about an Ag(I) atom. In the tetranuclear complex 4, two linearly coordinated Ag(I) atoms lying on the molecular C2 axis are bridged by a pair of ntb ligands and the remaining pendant arm of each ntb ligand is attached to another Ag(I) atom whose tetrahedral coordination sphere is completed by an acetonitrile molecule and a chelating trifluoroacetate anion. Complexes 2 and 3 may be regarded as an aggregation of two tridentate ligands by a silver dimer and a trinuclear cluster with weak Ag...Ag interactions, respectively, while in 4 the aggregation of two tripodal ligands by four Ag(I) ions affords a multicomponent internal cavity. The packing modes of complexes 1-3 are dominated by weak supramolecular pi...pi and CH...pi interactions. Hexagonal or square channels are generated in 1 and 2, and a honeycomb layer structure is formed in 3 with solvate molecules and counteranions occupying the voids. The crystal structure of 4 consists of a three-dimensional network consolidated by NH...O and OH...O hydrogen bonds.     

Different nuclearity silver(I) complexes with novel tetracyano pendant-armed hexaazamacrocyclic ligands

A new series of different nuclearity silver(I) complexes with a variety of tetracyano pendant-armed hexaazamacrocyclic ligands containing pyridine rings (Ln) has been prepared starting from the nitrate and perchlorate Ag(I) salts in acetonitrile solutions. The ligands and complexes were characterized by microanalysis, conductivity measurements, IR, Raman, electronic absorption and emission spectroscopy, and L-SIMS spectrometry. (1)H NMR titrations were employed to investigate silver complexation by ligands L3 and L.(4) The compounds [Ag2L2(NO3)2] (2), ([Ag2L2](ClO4)2.2CH3CN)(infinity) (4), [AgL3](ClO(4)).CH3CN (5), and [Ag4(L4)2(NO3)2](NO3)2.4CH3CN.2H2O (7) were also characterized by single-crystal X-ray diffraction. The complexes have different nuclearities. Complex 2 is dinuclear with an {AgN3O2} core and a significant intermetallic interaction, whereas complex 4 has a polymeric structure formed by dinuclear distorted {AgN4} units joined by nitrile pendant arms. Compound 5 is mononuclear with a distorted {AgN2} linear geometry, and complex 7 consists of discrete units of a tetranuclear array of silver atoms with {AgN3O} and {AgN4} cores in distorted square planar environments. Complexes 2 and 4 were found to be fluorescent in the solid state at room temperature because of the Ag-Ag interactions.     

Self-assembly of a cyclic metalladecapyridine from the reaction of 2,6-bis(bis(2-pyridyl)methoxymethane)pyridine with silver(I)

Reaction of Ag( p-MeC 6H 4SO 3) with 2,6-bis(bis(2-pyridyl)methoxymethane)pyridine (PY5) in CH 2Cl 2 gave [Ag (I) 2(PY5) 2](p-MeC 6H 4SO 3) 2 (1). Treatment of 2,6-bis(bis(2-pyridyl)hydroxymethane)pyridine (PY5-OH) with AgNO 3 in MeOH gave [Ag (I) 2(PY5-OH) 2](NO3) 2 (2); in the presence of PPh 3, this reaction afforded [Ag (I)(PY5-OH)(PPh 3)]NO 3 (3). The structures of 1- 3 have been determined by X-ray crystal analysis, revealing four-coordinate Ag (I) ions in these complexes. Both 1 and 2 feature a quadruply branched 28-membered C 16N 10M 2 metallamacrocycle fused to 10 pyridyl groups. On the basis of (1)H NMR measurements, the dinuclear 1 and 2 dissociate into a mononuclear complex upon dissolving in MeCN but in MeOH an equilibrium between the mono- and dinuclear species can be detected.     

新型含2,5-二-（3,5-二甲基吡唑-4-巯基）-1,3,4-噻二唑-M(M=Co2+,Cd2+,Mn2+)配合物的合成、晶体结构及其抑菌活性研究

将配体L[2,5-二-(3,5-二甲基吡唑-4-巯基)-1,3,4-噻二唑]与Co(NO3)2 6H2O,Cd(NO3)2 4H2O和MnCl2 4H2O进行配位反应,得到三个配合物[Co(L)2(H2O)4](NO3)2 4(CH3CH2OH)(1),[Cd(L)2(H2O)4](NO3)2 4(CH3CH2OH)(2),[Mn(L)2(Cl)2(CH3OH)2]2(CH3OH)(3),并用元素分析,FT-IR和X射线单晶衍射进行了表征.分析结果表明,配体L呈"U"形,配合物1～3呈"S"形.配合物中Co(II),Cd(II),Mn(II)的配位环境均为扭曲八面体,每个金属离子同时和两个配体进行配位.配体和配合物体外抑菌活性研究结果表明,配体及其配合物都有一定的抑菌活性.     

Silver(I) complexes with oxazoline-containing tripodal ligands: structure variation via counter anions and reaction conditions

Seven new silver(I) complexes of the formula [Ag2(L)2(CF3SO3)2] (1), [Ag2(L)2(CH3SO3)2] (2) [Ag2(L)2](BF4)2 (3), [Ag3(L)2(NO3)2]NO3.5H2O (4), [Ag2(L)(NO3)2].CH3OH (5), [Ag2(L)2](ClO4)2 (6) and [Ag3(L)2(CH3CN)3](ClO4)3 (7) have been synthesized by reactions of 1,3,5-tris(2-oxazolinyl)benzene (L) with varied silver(I) salts under different conditions. The influences of counter anions and reaction conditions on the structure of the complexes are discussed. Three complexes , 1, 2 and 3 with two kinds of different 1D chain structures were obtained under the same synthetic conditions by using different silver(I) salts, and the ligand L was found to adopt bis-monodentate (1 and 2) and tris-monodentate (3) coordination modes respectively. On the other hand, by using the same silver(I) nitrate or silver(I) perchlorate but different reaction solvents, 4 and 5 or 6 and 7 were isolated respectively. Complexes 4and 5 have different 1D chain structures, and 6 is isostructural with . However, 7 is a tri-nuclear, propeller-shaped M3L2 supramolecular capsule in which L adopts a cis,cis,cis-conformation, while the ligand L in 3-6 has cis,trans,trans-conformation. The results revealed that the nature of the counter anions, such as their size, coordination ability and coordination mode, and the reaction conditions all have great impact on the structure of the complexes. The complexes were also characterized by electrospray mass spectrometry. Furthermore, complex 7 exhibited modest second-harmonic-generation (SHG) efficiency.     

Variable coordination modes of NO2(-) in a series of Ag(I) complexes containing triorganophosphines, -arsines,and -stibines. Syntheses,spectroscopic characterization (IR, 1H and 31P NMR,electrospray ionization mass), and structures of [AgNO2(R(3)E)(x)] adducts (E = P,As, Sb,x = 1-3)

Adducts of triorganophosphine, triphenylarsine, and triphenylstibine with silver(I) nitrite have been synthesized and characterized both in solution ((1)H, (31)P NMR) and in the solid state (IR, single-crystal X-ray structure analysis). In addition aggregates of AgNO(2) and ER(3) (E = P, As, Sb) have been identified in solution by electrospray ionization mass spectrometry (ESI-MS). The topology of the structures in the solid state was found to depend on the nature of ER(3) and on the stoichiometric ratio AgNO(2):ER(3). The adducts AgNO(2):EPh(3) (1:1) (E = P or Sb) are one-dimensional polymers, the role of NO(2)(-) being to bridge successive metal atoms by coordination of the two oxygens to one silver atom and the nitrogen lone pair to a successive Ag. The adduct AgNO(2):P(o-tolyl)(3) (1:1) is mononuclear, due to steric hindrance of the phosphine, the nitrite being O,O'-bidentate, a rare example of a quasi-linear P-Ag-X array. AgNO(2):P(p-F-C(6)H(4))(3) (1:1) is a dimer, the nitrite being coordinated through both oxygens, the first unidentate, the second bridging bidentate. P(o-tolyl)(3) and Pcy(3) form 1:2 adducts, also mononuclear, the nitrite still an O,O'-chelate. In contrast, the adduct AgNO(2):AsPh(3) (1:2) is a centrosymmetric dimer, essentially an aggregate of a pair of [Ag(O(2)N)(AsPh(3))(2)] arrays with one nitrite oxygen being the bridging atom. The adducts AgNO(2):EPh(3) (1:3) (E = As, Sb) are mononuclear, the nitrite behaving as a consistently strong O,O'-chelate. The E = As adduct is a triclinic solvated form, whereas the unsolvated E = Sb species is monoclinic. ESI-MS spectra of acetonitrile solutions of these complexes show the existence of [Ag(ER(3))](+), [Ag(CH(3)CN)](+), [Ag(CH(3)CN)(2)](+), [AgCl(2)](-), [Ag(NO(2))(2)](-), [Ag(ER(3))(CH(3)CN)](+), and [Ag(ER(3))(2)](+) as well as higher aggregates [Ag(2)(NO(2))(ER(3))(2)](+), [Ag(2)(NO(2))(3)](-) and [Ag(2)Cl(2)(NO(2))](-), which are less prevalent.     

Extended coordination frameworks incorporating heterobimetallic squares

The molecular structure of aluminium and iron(III) complexes with 3-phenyl and 3-(4-pyridyl) (HL) substituted acetylacetonate ligands is appreciably distorted. For AlL3 and FeL3 this shows that the orientation of the side pyridyl-N donor atoms lone pairs is about 90 and 135 degrees which favours the assembly of heterobimetallic square patterns in Al(Fe)L3 complexes with metal ions. This was employed for the modular construction of semi-regular heterobimetallic networks, in which the pyridyldiketonate ligands bridge pairs of Fe(Al)/Cd(Co) metal ions and support the structure of 1D and 2D coordination polymers. The unprecedented 2D structure of [Cd[AlL3](CH3OH)[NO3]2].2CHCl3 and Cd[AlL3](CH3OH)Br2].2CHCl3 . 2CH3OH is based upon plane tiling by a set of heterobimetallic squares and octagons, while [Cd[FeL3]2(NO3)2].2H2O and [Co[AlL3]2Cl2].4CHCl3 . 2CH3OH are 1D polymers and exist as chains of heterobimetallic squares sharing opposite vertices.     

Disilver(I) rectangular-shaped metallacycles: X-ray crystal structure and dynamic behavior in solution

Reaction of the ditopic semirigid ligand 1,2-bis(imidazolylmethyl)benzene (1,2-bImb) or the flexible ligand 1,4-bis(2-benzimidazolyl)butane (C4BIm) with AgX (X = ClO4-, BF4-, CF3CO2-) afforded five new complexes, namely, [Ag2(1,2-bImb)2](ClO4)2 (1), [Ag2(1,2-bImb)2](BF4)2 (2), [Ag2(1,2-bImb)2](CF3CO2)2.2CH3OH (3.2CH3OH), [Ag2(C4BIm)2](ClO4)2.2DMF (4.2DMF), and [Ag2(C4BIm)2](CF3CO2)2.2H2O (5.2H2O), all of which contain a centrosymmetric, rectangular-shaped cationic disilver(I) metallacycle [Ag2(L)2]2+. In 1-3, a pair of 1,2-bImb ligands takes on the syn conformation to connect two Ag(I) ions to give a compressed rectangle with a transannular Ag...Ag separation of 3.27-3.36 angstroms, whereas in 4 and 5, the pair of planar C4BIm ligands acts in the cis conformation to connect two Ag(I) ions to yield a normal rectangle with a transannular Ag...Ag separation of 7.67-7.91 angstroms. The anions form Ag...O or Ag...F weak interactions in 1-3 and O-H...O or N-H...O hydrogen bonds in 4 and 5 in crystal packing but exhibit no significant influence on the formation of the disilver(I) macrocycles. The solution structure and dynamic behavior of the complexes studied by electrospray ionization mass spectrometry, 1H NMR, and variable-temperature NMR indicated that the dynamic equilibrium between the [Ag2(L)2]2+ cation and the open-ring oligomers or other potential species occurs via solvent-assisted dissociative exchange. The metal-ligand exchange barrier was estimated to be 54.5 kJ mol(-1).     

双吡啶化合物3，7-di(3-pyridyl)-1，5-dioxa-3，7-diazacyclooctane构建的四个过渡金属配合物的合成、结构及热稳定性

采用准刚性的双吡啶化合物3,7-di(3-pyridyl)-1,5-dioxa-3,7-diazacyclooctane(L),合成了4个过渡金属配合物[Co(NO3)(H2O)2(L)2]NO3(1)、[Co2Cl4(L)2]·CH2Cl2(2)、[Cd2(AcO)4(L)2]·4CH3OH(3)和[Cd2(NO3)2(CH3OH)2(H2O)2(L)2](NO3)2·2H2O(4)。单晶衍射分析表明,配合物1是单核结构,配合物2是24-元环状双核结构,而配合物3和4为多边形双核结构。在这些配合物中,双吡啶配体分别采用了单齿、trans-和cis-桥连3种不同配位方式。配合物经过了元素分析、红外、热重和X射线单晶结构分析表征。     

Coordination Triangular Prism of Bisilver Complex with Triply—bridged of Bis（diphenylphosphino）amine

1 INTRODUCTION Recently coinage metal complexes of poly- dentate phosphines are of great interest owing to the applications in diverse areas such as supramolecular design, photophysics and catalysis[1～4]. It is well- known that the binuclear coinage metal complexes of diphosphine [M2(diphosphine)2(MeCN)2]2+ (M = Cu, Ag, Au)[5～16] are excellent precursors for the design of polynuclear or polymeric materials with desired properties due to the easy substitution of weakly coordinated ac…     

Synthesis of nitrosylruthenium complexes containing 2,2':6',2"-terpyridine by reactions of alkoxo complexes with acids

Nitrosylruthenium complexes containing 2,2':6',2"-terpyridine (terpy) have been synthesized and characterized. The three alkoxo complexes trans-(NO, OCH3), cis-(Cl, OCH3)-[RuCl(OCH3)(NO)(terpy)]PF6 ([2]PF6), trans-(NO, OC2H5), cis-(Cl, OC2H5)-[RuCl(OC2H5)(NO)(terpy)]PF6 ([3]PF6), and [RuCl(OC3H7)(NO)(terpy)]PF6 ([4]PF6) were synthesized by reactions of trans-(Cl, Cl), cis-(NO, Cl)-[RuCl2(NO)(terpy)]PF6 ([1]PF6) with NaOCH3 in CH3OH, C2H5OH, and C3H7OH, respectively. Reactions of [3]PF6 with an acid such as hydrochloric acid and trifluoromethansulforic acid afford nitrosyl complexes in which the alkoxo ligand is substituted. The geometrical isomer of [1]PF6, trans-(NO, Cl), cis-(Cl, Cl)-[RuCl2(NO)(terpy)]PF6 ([5]PF6), was obtained by the reaction of [3]PF6 in a hydrochloric acid solution. Reaction of [3]PF6 with trifluoromethansulforic acid in CH3CN gave trans-(NO, Cl), cis-(CH3CN, Cl)-[RuCl(CH3CN)(NO)(terpy)]2+ ([6]2+) under refluxing conditions. The structures of [3]PF6, [4]PF6.CH3CN, [5]CF3SO3, and [6](PF6)2 were determined by X-ray crystallograpy.     

2[Mn(acacen)]+ + 1[Fe(CN)5NO]- polynuclear heterobimetallic coordination compounds of different dimensionality in the solid state

Depending on the synthetic conditions, five heterometallic Mn(III)Fe(II) polynuclear compounds with the same ratio of constituents, 2[Mn(acacen)](+)/[Fe(CN)(5)NO](2-), of different nuclearity and dimensionality (0D, 1D, 2D) were isolated. A [Mn(acacen)MeOH](2)[Fe(CN)(5)NO]·1.5MeOH, 1 complex has been prepared by reaction of Mn(III)/Schiff base (SB) complex, [Mn(acacen)Cl] (H(2)acacen is N,N'-ethylenebis(acetylacetoneimine)) with sodium nitroprusside (NP). Single crystal X-ray diffraction analyses reveal that crystallization of 1 from coordinating or non-coordinating solvents results in different coordination polynuclear materials: from C(2)H(5)OH [{Mn(acacen)H(2)O}(2)Fe(CN)(5)NO]·C(2)H(5)OH, 2, a trinuclear complex is formed; from CH(3)CN [{Mn(acacen)H(2)O}(4)Fe(CN)(5)NO][Fe(CN)(5)NO]·4CH(3)CN, an ionic compound with a pentanuclear bimetallic cation is formed 3; from i-C(3)H(7)OH [{Mn(acacen)}(2)(i-PrOH)Fe(CN)(5)NO](n), a coordination chain polymer 4 is formed; from toluene [{Mn(acacen)}(2)Fe(CN)(5)NO](n), a layered network 5 is formed. As the magnetic measurements show, for all compounds the weak interaction between Mn(III)S = 2 spins through the NP bridge is antiferromagnetic and exhibits no significant photoactivity.     

Entanglement of individual coordination polymers having helicates as building intermediates

A series of Ag(I) coordination compounds, from one-dimensional chains to 3D porous frameworks, were achieved from N,N'-bis[1-(2-pyrazinyl)ethylidene]benzil dihydrazone, L, via self-assembly, using helicates as effective secondary building units. Compound 2 [(Ag(2.75)L)(NO(3))(2.75)] was comprised of two opposite-handed 3D frameworks formed by connecting the 4(1) helical chains into (10(3)-b) nets. The pairs of the racemic 3D frameworks were connected through additional silver(I) centers and entangled each other forming a racemic 3D net. Compound 3 [(Ag(13)L(8))(BF(4))(13)(H(2)O)(12)] was comprised of a 3D framework that was constructed from double-helical building intermediates Ag(2)L(2) with one-dimensional infinite chains being threaded into the large voids of a 3D framework to form a weave structure. The ladder-like chains in compound 4 [(Ag(3)L(2))(ClO(3))(3)(CH(3)OH)(2)(CH(3)CN)] were formed by the addition of excess NaClO(3) into the methanol solution containing AgNO(3) and the ligand L, and the zigzag chains in compound 5 [(Ag(2)L(2))(ClO(4))(2)(CH(3)CN)(2)] were constructed by the addition of excess NaClO(4) into an acetonitrile solution containing AgNO(3) and the ligand L.     

Structural and spectroscopic evidence for the formation of trinuclear and tetranuclear vanadium(III)/carboxylate complexes of acetate and related derivatives in aqueous solution

The formation of vanadium(III) complexes with nuclearity greater than two is believed to occur in aqueous solution on the basis of potentiometric, electrochemical, and/or UV-vis spectroscopy titration measurements, although structural evidence for this is limited. Upon the addition of 1-2 equiv of acetate, propionate, chloroacetate, trifluoroacetate, or bromoacetate to an aqueous, acidic solution of vanadium(III), trinuclear and tetranuclear complexes are formed. The structures of [V4(mu-OH)4(mu-OOCCF3)4(OH2)8]Cl4.7.5H2O (1), [V4(mu-OH)4(mu-OOCCH3)4(OH2)8]Cl4.CH3COOH.12H2O (2), [V4(mu-OH)4(mu-OOCCH3)4(OH2)8]Cl4.3H2O (3), [V3(mu3-O)(mu-OOCCH2Br)6(OH2)3]CF3SO3.H2O (4), [V3(mu3-O)(mu-OOCCH2CH3)6(OH2)3]Cl.2H2O (5), [V3(mu3-O)(mu-OOCCH3)6(OH2)3]Cl.3.5H2O (6), and [V3(mu3-O)(mu-OOCCH2Cl)6(OH2)3]CF3SO3.H2O (7) have been determined by X-ray diffraction. Importantly, electrospray mass spectrometry and 1H NMR measurements suggest that these complexes are not purely solid-state phenomena but are also present in solution. For the vanadium(III)/acetate and vanadium(III)/propionate systems, two paramagnetic 1H NMR signals corresponding to two distinct complexes (species A and B) are observed in the 40-55 ppm region for 0.20 mol equiv of acetate or propionate, at pD 3.44. No corresponding signals are observed for the vanadium(III)/bromoacetate and vanadium(III)/chloroacetate systems under the same conditions or for the vanadium(III)/ trifluoroacetate system using 19F NMR spectroscopy. UV-vis spectra suggest that species B are structurally analogous for the vanadium(III)/acetate and vanadium(III)/propionate systems, whereas structurally different complexes are the major species for the other systems. Diffusion coefficients of species B for the vanadium(III)/acetate and vanadium(III)/propionate systems determined by pulsed-field-gradient spin-echo NMR spectroscopy measurements are (3.0 +/- 0.1) x 10-6 and (3.23 +/- 0.01) x 10-6 cm2 s-1, respectively, and are most consistent with species B being trimeric, rather than tetranuclear, complexes.     

Self-assembly of D-penicillaminato M6M'8 (M = Ni(II), Pd(II), Pt(II); M' = Cu(I), Ag(I)) clusters and their organization into extended La(III)M6M'8 supramolecular structures

A series of chiral M(6)M'(8) cluster compounds having twelve free carboxylate groups, [M(6)M'(8)(D-pen-N,S)(12)X](5-) (M/M'/X = Pd(II)/Ag(I)/Cl(-) ([1](5-)), Pd(II)/Ag(I)/Br(-) ([2](5-)), Pd(II)/Ag(I)/I(-) ([3](5-)), Ni(II)/Ag(I)/Cl(-) ([4](5-)), Pt(II)/Ag(I)/Cl(-) ([5](5-)), Pd(II)/Cu(I)/Cl(-) ([6](5-)); D-H(2)pen = D-penicillamine), in which six cis-[M(D-pen-N,S)(2)](2-) square-planar units are bound to a [M'(8)X](7+) cubic core through sulfur-bridges, was synthesized by the reactions of cis-[M(D-pen-N,S)(2)](2-) with M' in water in the presence of halide ions. These M(6)M'(8) clusters readily reacted with La(3+) in aqueous buffer to form La(III)(2)M(6)M'(8) heterotrimetallic compounds, La(2)[1](CH(3)COO), La(2)[2](CH(3)COO), La(2)[3](CH(3)COO), La(2)[4](CH(3)COO), La(2)[5](CH(3)COO) and La(2)[6]Cl, in which the M(6)M'(8) cluster units are linked by La(3+) ions through carboxylate groups in a 1?:?2 ratio. While the La(III)(2)M(6)Ag(I)(8) compounds derived from [1](5-), [2](5-), [3](5-), [4](5-) and [5](5-) have a 1D helix supramolecular structure with a right-handedness, the La(III)(2)Pd(II)(6)Cu(I)(8) compound derived from [6](5-) has a 2D sheet-like structure with a triangular grid of the Pd(II)(6)Cu(I)(8) cluster units. When aqueous HCl was added to the reaction solution of [6](5-) and La(3+), another La(III)(2)Pd(II)(6)Cu(I)(8) heterotrimetallic compound, La(2)[6]Cl·HCl, in which the Pd(II)(6)Cu(I)(8) cluster units are linked by La(3+) ions to form a 2D structure with a rectangular grid, was produced. The solid-state structures of these La(III)(2)M(6)M'(8) compounds, determined by single-crystal X-ray crystallography, along with the spectroscopic properties of the M(6)M'(8) cluster compounds in solution, are described.     

Discrete and infinite cage-like frameworks with inclusion of anionic and neutral species and with interpenetration phenomena

Complex [Ag(tpba)N(3)] (1) was obtained by reaction of novel tripodal ligand N,N',N"-tris(pyrid-3-ylmethyl)-1,3,5-benzenetricarboxamide (TPBA) with [Ag(NH(3))(2)]N(3). While the reactions between 1,3,5-tris(imidazol-1-ylmethyl)-2,4,6-trimethylbenzene (TITMB) and silver(I) salts with different anions and solvent systems give six complexes: [Ag(3)(titmb)(2)](N(3))(3).CH(3)OH.4 H(2)O (2), [Ag(3)(titmb)(2)](CF(3)SO(3))(2)(OH).5 H(2)O (3), [Ag(3)(titmb)(2)][Ag(NO(3))(3)]NO(3).H(2)O (4), [Ag(3)(titmb)(2)(py)](NO(3))(3).H(2)O (py=pyridine) (5), [Ag(3)(titmb)(2)(py)](ClO(4))(3) (6), and [Ag(3)(titmb)(2)](ClO(4))(3).CHCl(3) (7). The structures of these complexes were determined by X-ray crystallography. The results of structural analysis of complexes 1 and 2, with the same azide anion but different ligands, revealed that 1 is a twofold interpenetrated 3D framework with interlocked cage-like moieties, while 2 is a M(3)L(2) type cage-like complex with a methanol molecule inside the cage. Entirely different structure and topology between 1 and 2 indicates that the nature of organic ligands affected the structures of assemblies greatly. While in the cases of complexes 2-7 with flexible tripodal ligand TITMB, they are all discrete M(3)L(2) type cages. The results indicate that the framework of these complexes is predominated by the nature of the organic ligand and geometric need of the metal ions, but not influenced greatly by the anions and solvents. It is interesting that there is a divalent anion [Ag(NO(3))(3)](2-) inside the cage 4 and an anion of ClO(4)(-) or NO(3)(-) spontaneously encapsulated within the cage of complexes 5, 6 and 7.     

Synthesis and spectroscopic characterization of silver(I) complexes with the bis(1,2,4-triazol-1-yl)alkane ligand tz2(CH2). X-ray structures of two- and three-dimensional coordination polymers

1:1 AgX:tz(2)(CH(2)) (X = NO(3), NO(2), ClO(4)), 3:4 (X = O(3)SCF(3) (=OTf), O(2)CCF(3) (= tfa)), and 2:1 adducts (X = BrO(3)) have been synthesized and characterized in the solid state and in solution by analyses, spectral (IR, far-IR, (1)H and (13)C NMR, ESI MS) data, and conductivity measurements. The crystal structures of the 1:1 AgNO(3):tz(2)(CH(2)) and AgNO(2):tz(2)(CH(2)) adducts determined by X-ray studies show that tz(2)(CH(2)) coordinates to silver through the exodentate nitrogen atoms at the 4-positions of the triazole rings, yielding neutral polymers, while the ionic Ag(OTf):tz(2)(CH(2)) (3:4) adduct has a three-dimensional polymeric cation. The NMR and ESI MS data suggest that tz(2)(CH(2)) is only weakly coordinating, adducts between Ag(I) and CH(3)CN being more prevalent in acetonitrile solution.