Coordination Networks Based on Tetrahedral Silane Building Blocks: Influence of the Anion on Structures Adopted by Ag+−Si(p-C6H4CN)4 Arrays

What's in an Atom? A Comparison of Carbon and Silicon-Centred Amidinium⋅⋅⋅Carboxylate Frameworks*

Despite their apparent similarity, framework materials based on tetraphenylmethane and tetraphenylsilane building blocks often have quite different structures and topologies. Herein, we describe a new silicon tetraamidinium compound and use it to prepare crystalline hydrogen bonded frameworks with carboxylate anions in water. The silicon-containing frameworks are compared with those prepared from the analogous carbon tetraamidinium: when biphenyldicarboxylate or tetrakis(4-carboxyphenyl)methane anions were used similar channel-containing networks are observed for both the silicon and carbon tetraamidinium. When terephthalate or bicarbonate anions were used, different products form. Insights into possible reasons for the different products are provided by a survey of the Cambridge Structural Database and quantum chemical calculations, both of which indicate that, contrary to expectations, tetraphenylsilane derivatives have less geometrical flexibility than tetraphenylmethane derivatives, that is, they are less able to distort away from ideal tetrahedral bond angles.

Tuning linkage isomerism and magnetic properties of bi- and tri-metallic cage silsesquioxanes by cation and solvent effects

The ability of the polynuclear cage metallasilsesquioxane [(PhSiO_1.5)₁₂(CuO)₄(NaO_0.5)₄(n-BuOH)₈] with a globular structure to act as a stable building block of hybrid materials with respect to the substitution of sodium cations and terminal butanol molecules was confirmed.

Dinuclear clathrochelate complexes with pendent cyano groups as metalloligands

Dinuclear clathrochelate complexes can be decorated with two, three, four, or five cyano groups. These complexes represent versatile metalloligands for the construction of coordination polymers.

Coordination Polymers of Silver(I) with the Flexible Tritopic Ligand 1,3,5-Tri(4-cyanophenoxy)benzene: Guest Inclusion and Luminescent Properties

A new flexible tritopic ligand, 1,3,5-tri(4-cyanophenoxy)benzene (1), was synthesised by the reaction of phloroglucinol and para-fluorobenzonitrile. Compound 1 crystallises in the non-centrosymmetric space group Pna21. The reaction of ligand 1 with AgBF4 in the presence of different aromatic guest molecules was found to result in coordination polymers, namely, {[Ag3(1)2(BF4)3(H2O)2]·2C7H8·2CH2Cl2}n (2), {[Ag3(1)2(BF4)3(H2O)2]·2C6H6·2CH2Cl2}n (3). The crystal structures of 2 and 3 reveal that ligand 1 is linked by AgI ions into three-dimensional networks containing channels that are occupied by dichloromethane and aromatic guest molecules. The luminescent properties of crystalline 1 and 3 differ significantly.

An unusual polycatenating network self-assembled by the 2D --> 2D parallel --> 3D parallel interpenetration of coordinative and hydrogen-bonded (6,3) motifs

In the title coordination compound, catena-poly[[[bis[diaquacadmium(II)]-mu(2)-trans-1,2-bis(4-pyridyl)ethene]bis{mu(2)-2,2'-[(5-carboxymethoxy-m-phenylene)dioxy]diacetato}] trans-1,2-bis(4-pyridyl)ethene solvate dihydrate], {[Cd(2)(C(12)H(10)O(9))(2)(C(12)H(10)N(2))(H(2)O)(4)].C(12)H(10)N(2).2H(2)O}(n), (I), each Cd(II) centre adopts a pentagonal-bipyramidal coordination geometry. The incompletely deprotonated 2,2'-[(5-carboxymethoxy-m-phenylene)dioxy]diacetate (TCMB) ligands and trans-1,2-bis(4-pyridyl)ethene (bpe) ligands both act as bidentate bridges, linking the Cd(II) centres into one-dimensional ladders, which are connected into an undulating two-dimensional (6,3) layer through O-H...N hydrogen bonds between the carboxylate groups of the TCMB ligands and the N atoms of the uncoordinated bpe ligands. Each undulating layer polycatenates two other identical layers, exhibiting the unusual combination of both 2D --> 2D parallel and 2D --> 3D parallel interpenetration (2D and 3D are two- and three-dimensional, respectively).

A novel bilayer cobalt(II)-organic framework with nanoscale channels accommodating large organic molecules

A unique noninterpenetrated 2D bilayer cobalt(II)-organic framework, [[Co(dpe)(NO(2)-BDC)].0.5(dpe)](n).nH(2)O (1), possessing nanoscale rectangular channels that clathrate large organic molecules, has been hydrothermally synthesized by reaction of cobalt(II) salt with 5-nitro-1,3-benzenedicarboxylic acid (NO(2)-H(2)BDC) and 1,2-bis(4-pyridyl)ethylene (dpe).

Gold-gold interactions as crystal engineering design elements in heterobimetallic coordination polymers

A series of coordination polymers containing Cu(II) and [Au(CN)(2)](-) units has been prepared. Most of their structures incorporate attractive gold-gold interactions, thus illustrating that such "aurophilic" interactions can be powerful tools for increasing structural dimensionality in supramolecular systems. [Cu(tren)Au(CN)(2)][Au(CN)(2)] (1, tren = tris(2-ethylamino)amine) forms a cation/anion pair, which is weakly linked by hydrogen bonds but not by aurophilic interactions. [Cu(en)(2)Au(CN)(2)][Au(CN)(2)] (2-Au, en = ethylenediamine) is a 2-D system composed of a chain of [Au(CN)(2)](-) anions and another chain of [(en)(2)Cu-NCAuCN](+) cations; short Au-Au bonds of 3.1405(2) A connect the anions. This bond is shorter than that observed in the analogous silver(I) structure, 2-Ag. The average M-C bond lengths of 1.984(8) A in 2-Au are significantly shorter than those found in 2-Ag, suggesting that Au(I) is smaller than Ag(I). Cu(dien)[Au(CN)(2)](2) (3, dien = diethylenetriamine) forms a 1-D chain of tetranuclear [Au(CN)(2)](-) units that are bound to [Cu(dien)] centers. Aurophilic interactions of ca. 3.35 A hold the tetramer together. Cu(tmeda)[Au(CN)(2)](2) (4, tmeda = N,N,N',N'-tetramethylethylenediamine) forms a 3-D network by virtue of aurophilic interactions of 3.3450(10) and 3.5378(8) A. Altering the Cu:Au stoichiometry yields Cu(tmeda)[Au(CN)(2)](1.5)(ClO(4))(0.5) (5), which has an unusual 2-D rhombohedral layer structure (space group R32). Complex 5 is composed of three mutually interpenetrating Cu[Au(CN)(2)](1.5) networks which are interconnected by aurophilic interactions of 3.4018(7) and 3.5949(8) A. Weak antiferromagnetic coupling is observed in 2 and 5.

2-D interwoven and 3-D 5-fold interpenetrating silver(I) complexes of 1-(isocyanidomethyl)-1H-benzotriazole and 1,3-bis(dicyanomethylidene)indan

This paper presents novel and distinctive organosilver polymers with intriguing structure motifs, constructed from iodoacetonitrile (L1), 1-(isocyanidomethyl)-1H-benzotriazole (L2), 1,3-bis(dicyanomethylidene)indan (L3), and silver(I) salts, respectively. Treatment of L1 with AgClO4 generated [Ag(L1)(ClO4)]n (1), whose X-ray determination revealed a 2-D wavy sheet structure with square grids. Reaction of L2 with AgPF6 gave rise to a novel 2-D wavy interwoven network, ([Ag(L2)(PO2F2)0.5])n (2). The complex [Ag2(L3)2]n (3) obtained by reaction of AgClO4 with L3 can be regarded as unprecedented 3-D 5-fold interpenetrating nets with columnar aromatic stacks and indicates semiconductive behavior. The IR, ESR spectroscopic results, conductivities, and structural features of the complexes are discussed, respectively. The present findings may provide insight into the coordination versatility of silver(I) and polynitrile ligands and an inspiration for the self-assembly of novel supramolecular networks with multifunctional ligands. Crystal data: 1, C2H2AgINClO4, orthorhombic, Pca2(1) (No. 29), a = 14.503(1) A, b = 5.104(2) A, c = 10.2019(9) A, Z = 4; 2, C8H6AgN4PF4O, orthorhombic, Pnna (No. 52), a = 12.2705(3) A, b = 21.150(1) A, c = 10.040(1) A, Z = 8; 3, C30H10Ag2N8, triclinic, P1 (No. 2), a = 14.920(2) A, b = 11.896(2) A, c = 7.400(4) A, alpha = 86.55(2) degrees, beta = 80.87(2) degrees, gamma = 74.47(1) degrees, Z = 2.