Group 2 metal salts of pyromellitic acid: [Mg(H2O)6](C10H4O8) and [Ba(C10H4O8)(H2O)5]

Structural determinations of the magnesium(II) and barium(II) salts of pyromellitic acid (benzene‐1,2,4,5‐tetra­carboxyl­ic acid) are presented. Hexa­aqua­magnesium(II) benzene‐1,2,4,5‐tetra­carboxyl­ate(2−), [Mg(H₂O)₆](C₁₀H₄O₈), (I), and penta­aqua­[benzene‐1,2,4,5‐tetra­carboxyl­ato(2−)]­barium(II), [Ba(C₁₀H₄O₈)(H₂O)₅], (II), are both centrosymmetric and both possess a 1:1 metal–ligand ratio, but the two structures are found to differ in that the magnesium salt contains a hexaaqua cation and possesses only hydrogen‐bonding interactions between cations and anions, while the barium salt exhibits coordination of the carboxyl­ate ligand to the nine‐coordinate metal centre. In (I), both ions sit on a 2/m site symmetry, and in (II), the cation and anion are located on m and i site symmetries, respectively.     

Zoledronate complexes. III. Two zoledronate complexes with alkaline earth metals: [Mg(C5H9N2O7P2)2(H2O)2] and [Ca(C5H8N2O7P2)(H2O)]n

Diaquabis[dihydrogen 1‐hydroxy‐2‐(imidazol‐3‐ium‐1‐yl)ethylidene‐1,1‐diphosphonato‐κ²O,O′]magnesium(II), [Mg(C₅H₉N₂O₇P₂)₂(H₂O)₂], consists of isolated dimeric units built up around an inversion centre and tightly interconnected by hydrogen bonding. The Mg^II cation resides at the symmetry centre, surrounded in a rather regular octahedral geometry by two chelating zwitterionic zoledronate(1−) [or dihydrogen 1‐hydroxy‐2‐(imidazol‐3‐ium‐1‐yl)ethylidene‐1,1‐diphosphonate] anions and two water molecules, in a pattern already found in a few reported isologues where the anion is bound to transition metals (Co, Zn and Ni). catena‐Poly[[aquacalcium(II)]‐μ₃‐[hydrogen 1‐hydroxy‐2‐(imidazol‐3‐ium‐1‐yl)ethylidene‐1,1‐diphosphonato]‐κ⁵O:O,O′:O′,O′′], [Ca(C₅H₈N₂O₇P₂)(H₂O)]_n, consists instead of a Ca^II cation in a general position, a zwitterionic zoledronate(2−) anion and a coordinated water molecule. The geometry around the Ca^II atom, provided by six bisphosphonate O atoms and one water ligand, is that of a pentagonal bipyramid with the Ca^II atom displaced by 0.19 Å out of the equatorial plane. These Ca^II coordination polyhedra are `threaded' by the 2₁ axis so that successive polyhedra share edges of their pentagonal basal planes. This results in a strongly coupled rhomboidal Ca₂–O₂ chain which runs along [010]. These chains are in turn linked by an apical O atom from a –PO₃ group in a neighbouring chain. This O‐atom, shared between chains, generates strong covalently bonded planar arrays parallel to (100). Finally, these sheets are linked by hydrogen bonds into a three‐dimensional structure. Owing to the extreme affinity of zoledronic acid for bone tissue, in general, and with calcium as one of the major constituents of bone, it is expected that this structure will be useful in modelling some of the biologically interesting processes in which the drug takes part.     

Synthesis and Crystal Structure of a Two-dimensional Coordination Polymer [Cd（dym）（H2O）2（H2O）]n with Cd6 Hexagonal Macrometallocycle

1 INTRODUCTION The investigation of coordination polymers has rapidly been expanded in last decade owing to their potential applications such as catalysis, molecular absorption, non-linear and magnetic materials. Among the varieties of such coordination polymers, the po- lymers of cadmium with dicarboxylates having fas- cinating structural topologies and good photolumi- nescence constitute a new family. Many reports are concerned about cadmium dicarboxylate polymers with 1D helix structu…     

Carboxylate-bridged copper(II)-lanthanide(III) complexes [(Cu(3)Ln(2)(oda)(6)(H(2)O)(6)).12H(2)O](n)(Ln = Dy,Ho, Er,Y; oda = oxydiacetate)

The hydrothermal reaction of Ln(2)O(3) (Ln = Dy and Ho), Cu(OAc)(2).2H(2)O, and oxydiacetic acid in the approximate mole ratio of 1:3:8 resulted in the formation of two new members of the isostructural series of polymers formulated as [(Cu(3)Ln(2)(oda)(6)(H(2)O)(6)).12H(2)O](n), crystallizing in the hexagonal crystal system, space group P6/mcc (No. 192). Temperature-dependent magnetic susceptibilities and EPR spectra are reported for the heterometallic compounds Cu-Dy 1, Cu-Ho 2, Cu-Er 3, and Cu-Y 4. The results are discussed in terms of the structure of the compounds, the electronic properties of the lanthanide ions, and the exchange interactions between the magnetic ions.     

Synthesis and magnetic properties of nickel(II) triazamacrocyclic complexes. Crystal structure of [Ni(Me3[12]N3)(O2N)(H2O)]-(ClO4)·2H2O

Summary The synthesis, properties and X-ray crystal structure of [Ni(Me₃[12]N₃)(O₂N)(H₂O)](ClO₄)·2H₂O, in which Me₃[12]N₃ is 2,4,4-trimethyl-1,5,9-triazacyclododec-1-ene, are described. The Ni atom is octahedrally coordinated to three N atoms of the macrocycle, two O atoms of the nitrito group and one H₂O molecule. Monomeric units are linked by hydrogen bonds through one of the water of crystallization molecules, forming a chain. Magnetic measurements between 290 and 4 K reveal slight antiferromagnetic behaviour.     

Comparison of two polymeric transition metal complexes with 1,4‐benzenedicarboxylate ions as bridging ligands, [Co(C8H4O4)(C12H8N2)(H2O)] and [Cu(C8H4O4)(C10H9N3)]·H2O

The title complexes, catena‐poly[[aqua(1,10‐phenanthroline‐κ²N,N′)­cobalt(II)]‐μ‐benzene‐1,4‐di­carboxyl­ato‐κ²O¹:O⁴], [Co(C₈H₄O₄)(C₁₂H₈N₂)(H₂O)], (I), and catena‐poly[[[(di‐2‐pyridyl‐κN‐amine)copper(II)]‐μ‐benzene‐1,4‐di­carboxyl­ato‐κ⁴O¹,O^1′:O⁴,O^4′] hydrate], [Cu(C₈H₄O₄)(C₁₀H₉N₃)]·H₂O, (II), take the form of zigzag chains, with the 1,4‐benzene­di­carboxyl­ate ion acting as an amphimonodentate ligand in (I) and a bis‐bidentate ligand in (II). The Co^II ion in (I) is five‐coordinate and has a distorted trigonal–bipyramidal geometry. The Cu^II ion in (II) is in a very distorted octahedral 4+2 environment, with the octahedron elongated along the trans O—Cu—O bonds and with a trans O—Cu—O angle of only 137.22 (8)°.     

Host-guest complexes [(H4L)(SiF6)2-4H2O] and [(H4L)(GeF6)2 4H2O] (L =meso-5,7,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane)

Synthesis and X-ray structure analysis of host-guest complexes [(H₄L)(SiF₆)₂-4H₂O] (I) and [(H₄L)(GeF₆)₂-4H₂O] (II) are reported (L = meso-5,7,7,12,12,14-hexamethyl-l,4,8,11-tetraazacyclo-tetradecane). The crystals of both compounds are triclinic with close unit cell parameters. I: a = 9.576(3), b= 9.217(3), c= 8.334(2) å, α= 105.66(2), Ω= 83.68(2), α = 105.38(2)? II: a= 9.627(3), b = 9.358(3), c.= 8.497(4) A, a= 106.02(2), Ω = 83.74(2), α= 106.06(2)?. The structural units of the crystals are the (H₄L)⁴⁺ cations, the hexafluorosilicate (or hexafluowgemanate) anions, and the water molecules linked by a system of H bonds. The macrocycle in the complexes has C₁ symmetry. In the inorganic anions, the silicon as well as germanium atom is surrounded by an octahedron of six fluorine atoms.

     

配合物(n-Bu)2Sn(C10H8N2O4)(C2H5OH)的合成和晶体结构

以2-羰基丙酸水杨酰腙作为配体与二正丁基氧化锡(Ⅳ)在苯/乙醇混合溶剂中反应, 合成了新型配合物(n-Bu)2Sn(C10H8N2O4)(C2H5OH)(C10H8N2O42为2-羰基丙酸水杨酰腙负二价离子)。用单晶X-射线衍射分析法测定了该配合物的晶体结构。晶体属四方晶系, I41/a空间群, 晶胞参数a = 2.5113(7), b = 2.5113(7), c = 1.5062(6) nm, V = 9.499(5) nm3, Z = 16, Dc = 1.396 g/cm3, m(MoKa) = 1.105 mm1, F (000) = 4096。对于2499 (I >2s(I))个可观测点, 最终可靠因子R = 0.0349, wR = 0.0793。在该配合物的分子结构中, 中心锡原子与3个O原子、1个N原子和2个C原子形成扭曲的八面体几何构型, 其中3个O原子和1个N原子为赤道配位原子, 而CSnC为配合物的轴。相邻配合物分子间因Sn…O的弱相互作用和分子间氢键的作用而以二聚体的结构形式存在。