Jency Thomas

Copper pyrazole directed crystallization of decavanadates: synthesis and characterization of {Cu(pz)}4[{Cu(pz)3}2V10O28] and (Hpz)2[{Cu(pz)4}2V10O28]·2H2O

Crystal engineering of two new fully oxidized decavanadate based 1-D solid {Cu(pz)4}[{Cu(pz)3}2V10O28], 1 and a 2-D inorganic–organic hybrid solid (Hpz)2[{Cu(pz)4}2V10O28]·2H2O, 2 have been effected under self-assembly condition. 1 contains 1-D anionic chains of the composition [{Cu(pz)3}2V10O28] intercalated with {Cu(pz)4}2+ as counter cations. 2 contains 2-D anionic sheets of the composition [{Cu(pz)4}2V10O28] incorporating pyrazolium counter cations and water molecules. Self-assembly of 1 and 2 is interpreted in terms of molecular recognition between reasonable soluble molecular species in the supramolecular reaction along the mechanistic approach proposed by Ramanan and Whittingham for rationalising metal–organic framework structures. Low temperature magnetic measurements of 1 and 2 show copper in divalent state with Curie behaviour. Crystal data: 1, triclinic, space group P-1, a = 11.671(1) A, b = 11.976(1) A, c = 12.900(1) A, α = 100.226(2)°, β = 105.549(3)°, γ = 118.571(2)°, Z = 1; 2, triclinic, space group P-1, a = 11.582(2) A, b = 11.659(1) A, c = 12.451(1) A, α = 114.660(3)°, β = 107.439(2)°, γ = 91.639(3)°, Z = 2.

Formation of high nuclearity mixed-valent polyoxovanadates in the presence of copper amine complexes

Two new Müller-type clusters, a one-dimensional solid [Cu(en)]24[Cl ⊂V15O36]−12H2O1, and a three-dimensional solid [Cu(pn)]24[Cl ⊂V18O42]·12H2O2, have been synthesised by employing identical hydrothermal conditions except varying the nature of organic diamine.1 crystallised in a chiral space groupP212121 witha = 12.757(1),b = 18.927(2) andc = 28.590(3) Å, andZ =4.2 crystallised in a tetragonal system with space groupP4/nnc,a = 15.113(1) andc = 18.542(3) Å, andZ = 2. Mixed-valent vanadium ions in structures1 and2 have been established both by magnetisation and bond-length bond-valence measurements. Chemistry of formation of high nuclearity polyoxovanadate clusters is discussed.

Understanding Supramolecular Interactions Provides Clues for Building Molecules into Minerals and Materials: a Retrosynthetic Analysis of Copper-Based Solids

The influence of non-covalent interactions on the crystal packing of molecules is well documented in the literature. Unlike molecular solids, crystal engineering of non-molecular solids is difficult to interpret as aggregation is complicated by the presence of neutral as well as ionic species and a range of forces operating, from weak hydrogen bonding to strong covalent interactions. In this perspective, we demonstrate for the first time the role of non-bonding interactions in the occurrence of oxide, hydroxide, or chloride linkages in oxides, hydroxychlorides, and chlorides of copper-based minerals and coordination polymers in terms of a mechanistic approach based on supramolecular retrosynthesis. The model proposed here visualizes the crystal nucleus as a supramolecular analogue of a transition state wherein appropriate tectons (chemically reasonable molecules) aggregate through non-bonding forces that can be perceived through well-known supramolecular synthons. The mechanistic approach provides chemical insights into the occurrence of different topologies and solid-state phenomena like polymorphism.