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Solvothermal reactions of a tricarboxylate ligand 5-(4-carboxybenzoylamino)-isophthalic acid (H3L), dipyridyl linkers (bpe, bpa and bpy) and divalent metal ions (Co2+, Cd2+, Zn2+ and Ni2+) provided a highly efficient approach to the syntheses of multi-dimensional framework materials containing interesting structural motifs: [Co3L2(bpe)4]·2DMF·2H2O (1), [Cd3L2(bpe)4]·3H2O (2), [Zn2L(OH)(bpe)]·5.5H2O (3), [Co7L4(bpa)2(OH)2(H2O)4]·4H2O (4), Ni(HL)(bpa)(H2O) (5) and [Zn2(HL)2(bpy)2(H2O)2]·(bpy)·6H2O (6) (bpe = 1,2-bis(4-pyridyl)ethene, bpa = 1,2-bis(4-pyridyl)diazene, bpy = 4,4′-bipyridine). Solids 1 and 2 are isostructural and each features a three-dimensional (3D) pillar-layer architecture generated from bpe-pillared M-L3− layers. Complex 3 has a 3D structure in which the secondary building unit (SBU) is a rare example of a tetranuclear Zn4(μ3-OH)2(COO)6(bpe)4 unit, whereas 4 exhibits an interesting sandwich-shaped architecture with a trimeric unit [Co3(COO)4(OH)(N2)] serving as the SBU. Complex 5 provides an unusual example of a (4,4) grid layer structure bearing free carboxylic acid (–COOH) units. The layered structure of 6 is generated from hydrogen bonded [Zn(HL)(bpy)(H2O)] chains, with free bpy and guest water molecules accommodated inside. Furthermore, the thermal behavior, powder X-ray diffraction (PXRD) and solid state photoluminescence properties correlated with the corresponding structural features were investigated. [ABSTRACT FROM AUTHOR]

Two trigonal prismatic bicyclooxacalixarenes1and2were obtained by condensation reaction of 1,3,5-tri(p-hydroxyphenyl)benzene and 2,4,6-tri(p-hydroxyphenyl)triazine, respectively, with 1,5-difluoro-2,4-dinitrobenzene. Single crystal structural analysis revealed that the bicyclooxacalixarene1adopts a distorted triangular prismatic structure. Bicyclooxacalixarene2, however, possesses an almostD3 hsymmetric triangular prismatic structure. The colorimetric changes in the acetone solutions of1or2upon addition of certain anions have been found highly relevant to the nitro-substituents in the phenyl pillars, not to their macrocyclic structures. [ABSTRACT FROM PUBLISHER]

C54H50N8O18Zn2, orthorhombic, Pbca (no. 61), a = 14.5349(5) Å, b = 17.3183(5) Å, c = 20.8872(7) Å, V = 5257.7(3) Å3, Z = 8, Rgt (F) = 0.0401, wRref( F2) = 0.1185, T = 293(2) K. [ABSTRACT FROM AUTHOR]

Highly selective anti-Markovnikov alkoxycarbonylation of alkenes over L2 -Pd(OAc) 2 catalytic system under mild conditions. [Display omitted] • Highly selective anti-Markovnikov alkoxycarbonylation of alkenes under mild conditions. • Bis-P,O-hybrid ligand of L2 with flexible meta - positioned dimethylene-phenyl backbone serving as a tripodal P,P,O-pincer with hemilability. • L2 conferring to Pd-catalyst the high activity and excellent regioselectivity. • L2 facilitating the formation and stability of Pd H active species. A series of bis-P,O-hybrid ligands (L1–L4) were synthesized and characterized. The crystal structures demonstrated that the ligand of L2 , 1,4-bis((2-(diphenylphosphaneyl)phenoxy)methyl)benzene, not only acted as a typical trans -positioned diphosphine as observed in the complexes Pd(L2)(OAc) 2 and Pd(L2)Cl 2 , but also potentially as a P,P,O-tripodal pincer. As a result, under mild conditions (80 °C, 0.5–3.0 MPa), L2 enabled Pd(OAc) 2 to exhibit remarkable performance in terms of high activity and excellent regioselectivity (l / b > 97/3) in the alkoxycarbonylation of vinyl arenes with the isolated yields of 57–91 %. [ABSTRACT FROM AUTHOR]

The effect of positive charges in the diphosphino-imidazolium salts of L2 was investigated in terms of coordinating character, structures of corresponding Ir-complexes and catalysis for hydroformylation. It was found that the involved positive charges exhibited strong electron-withdrawing effect on the neighbored phosphine fragment, rendering L2 more π -acceptor ability than the corresponding neutral counterpart of L1 . Consequently, the changed coordinating ability of L1 and L2 led to the variety in the structures and components for the Ir-complexes ( Ir-L1a , Ir-L1b , Ir-L2a , and Ir-L2b ). The complexation of L2 with Ir(acac)(CO) 2 led to a novel five-coordinate Ir(II)-complex of Ir-L2a chelated by a PCC (phosphine–carboanion–carbene) pincer in tripodal mode, whereas the complexation of L1 with Ir(acac)(CO) 2 led to a four-coordinate square-planar Ir(I)-complex of Ir-L1a chelated by a PCP (phosphine–carboanion–phosphine) pincer. In addition, the different catalytic performances of these Ir-complexes ligated by L1 and L2 for hydroformylation of olefins were investigated. [ABSTRACT FROM AUTHOR]

4,4′,4″-nitrilotribenzoic acid (H 3 L), a C 3 -symmetric ligand, was found to self-assemble into two polymorphs driven by intermolecular hydrogen-bonding interactions. Reactions of this ligand with Zn 2+ under solvothermal conditions resulted in four new coordination polymers bearing interesting structural motifs: [Zn 2 (L) 2 (py) 2 ]·2(H 2 NMe 2 ) + ·DMF·2H 2 O (1) , [Zn 2 (L)(H 2 L)(bipy)]·1.5H 2 O·Guest (2) , [Zn 2 (L) 2 (bipy)]·2(H 2 NMe 2 ) + ·2DMF (3) , and [Zn 3 (L) 2 (bpa)]·2H 2 O·Guest (4) (H 3 L=4,4′,4′′-nitrilotribenzoic acid, DMF=dimethylformamide, py=pyridine, bipy=4,4′-bipyridine, bpa=1,2-bis(4-pyridyl)diazene). Single-crystal structural analysis revealed that compound 1 exhibits a rare example of twofold interpenetrating anionic 3D (3,3)-net framework containing helical channels, whereas in 2 , the 3D pillar-layer structure generated from bipy-pillared Zn 2 (L)(H 2 L) layer is further reinforced by intermolecular hydrogen bonding among pairs of free –COOH units. Compound 3 shows an interesting entangled architecture of 2D→3D parallel polycatenation consisting five-coordinated Zn 2+ ions. Compound 4 displays a 3D pillar-layer framework with trimeric Zn 3 (CO 2 ) 6 serving as secondary building unit (SBU). The syntheses, structures, thermal stabilities, powder X-ray diffractions and solid-state photoluminescence properties for these crystalline materials have been carried out. In addition, supramolecular assembly of H 3 L under solvothermal conditions will also be addressed. [ABSTRACT FROM AUTHOR]

Abstract: 4,4′,4″-[1,3,5-Benzenetriyltris(carbonylimino)]trisbenzoic acid (H3L), a C 3-symmetric ligand, was found to self-assemble into an interesting core-rosette structure driven by intermolecular hydrogen-bonding interactions. Reactions of this ligand with Zn2+, Co2+ and Cd2+ under solvothermal conditions resulted in the formation of four new coordination polymers with interesting structural motifs: [Zn2(L)(OH)(H2O)(DMF)]·DMF·H2O (1), [Co3(L)2(DMF)(H2O)]·DMF·3CH3OH (2), [Co1.5(L)(H2O)(DMF)]·DMF (3), and [Cd1.5(L)(H2O)(DMF)]·DMF (4). Single-crystal structural analysis revealed that complex 1 exhibits a rare example of twofold interpenetrating two-dimensional CdI2-type structure with tetranuclear Zn4(μ 3-OH)2(COO)6(H2O)(DMF) serving as secondary building unit (SBU), whereas in 2, the μ3 -oxo-tricobalt basic carboxylate SBUs are connected by L3− ligands, leading to a twofold interpenetrating three-dimensional (3,6)-net framework. The isomorphous complexes 3 and 4 each has a (4,4)-grid layered architecture in which the SBU is a linear Co3/Cd3 cluster. The four coordination polymers were all further characterized by IR, thermogravimetric and powder X-ray diffraction (PXRD). [Copyright &y& Elsevier]

The complexes [Co(Him)2(μ4-bta)1/2]n 1 and {[Cu(phen)(μ4-bta)1/2]·H2O}n 2 were hydrothermally synthesized at 160°C and their structures were determined by single-crystal X-ray diffraction. Complex 1 was triclinic, space group P–1, a=7.9294(11) A˚, b=9.621(3) A˚, c=9.6461(16) A˚, α=116.772(19)°, β=96.791(13)°, γ=102.787(19)°, Z=2, V=620.3(2) A˚3, R1=0.0252 and wR2=0.0640 [I>2σ(I)]; complex 2 was monoclinic, space group P21/c, a=7.386(3) A˚, b=12.723(4) A˚, c=15.831(3) A˚, β=102.66(2)°, Z=4, V=1451.5(7) A˚3, R1=0.0389 and wR2=0.1033 [I>2σ(I)]. In both of the structures the metal ions were linked by the μ4-bridging benzene-1,2,4,5-tetracarboxylate ligands, resulting in one-dimensional double-metal chains. The synthesized products were characterized by IR spectroscopy, UV–VIS spectra, inductively coupled plasma (ICP), elemental, thermogravimetric (TGA) and magnetic analyses. [Copyright &y& Elsevier]