Synthesis, crystal structure and Hirshfeld surface analysis of di-acetato-bis-[4-(2-amino-eth-yl)morpholine]cadmium tetra-hydrate

The title coordination compound, [Cd(C2H3O2)2(C6H14N2O)2]·4H2O, was synthesized by mixing 2 moles of 4-(2-amino-eth-yl)morpholine and 1 mole of cadmium acetate in double-distilled water. The Cd atom is octa-hedrally coord-inated by two N,N'-bidentate ligands [4-(2-amino-eth-yl)morpholine] and two trans-located acetate mol-ecules. The Cd atom is located on a center of inversion, whereas the 4-(2-amino-eth-yl)morpholine and four water mol-ecules are adjacent to the acetate mol-ecules. The chair conformation of the morpholine mol-ecules is confirmed. In the crystal, adjacent metal complexes and uncoord-inated water mol-ecules are linked via N-H⋯O and O-H⋯O hydrogen-bonding inter-actions, generating R 2 2(6), R 6 6(16), R 6 6(20) and S 1 1(6) motifs and forming a three-dimensional network. A Hirshfeld surface analysis indicated the contributions of various contacts: H⋯H (71.8%), O⋯H/H⋯O (27.1%), and C⋯H/H⋯C (1.0%).

Beyond the Simple Copper(II) Coordination Chemistry with Quinaldinate and Secondary Amines

Copper(II) acetate has reacted in methanol with quinaldinic acid (quinoline-2-carboxylic acid) to form [Cu(quin)₂(CH₃OH)]∙CH₃OH (1) (quin⁻ = an anionic form of the acid) with quinaldinates bound in a bidentate chelating manner. In the air, complex 1 gives off methanol and binds water. The conversion was monitored by IR spectroscopy. The aqua complex has shown a facile substitution chemistry with alicyclic secondary amines, pyrrolidine (pyro), and morpholine (morph). trans-[Cu(quin)₂(pyro)₂] (2) and trans-[Cu(quin)₂(morph)₂] (4) were obtained in good yields. The morpholine system has produced a by-product, trans-[Cu(en)₂(H₂O)₂](morphCOO)₂ (5) (morphCOO⁻ = morphylcarbamate), a result of the copper(II) quinaldinate reaction with ethylenediamine (en), an inherent impurity in morpholine, and the amine reaction with carbon dioxide. (pyroH)[Cu(quin)₂Cl] (3) forms on the recrystallization of [Cu(quin)₂(pyro)₂] from dichloromethane, confirming a reaction between amine and the solvent. Similarly, a homologous amine, piperidine (pipe), and dichloromethane produced (pipeH)[Cu(quin)₂Cl] (11). The piperidine system has afforded both mono- and bis-amine complexes, [Cu(quin)₂(pipe)] (6) and trans-[Cu(quin)₂(pipe)₂] (7). The latter also exists in solvated forms, [Cu(quin)₂(pipe)₂]∙CH₃CN (8) and [Cu(quin)₂(pipe)₂]∙CH₃CH₂CN (9). Interestingly, only the piperidine system has experienced a reduction of copper(II). The involvement of amine in the reduction was undoubtedly confirmed by identification of a polycyclic piperidine compound 10, 6,13-di(piperidin-1-yl)dodecahydro-2H,6H-7,14-methanodipyrido[1,2-a:1′,2′-e][1,5]diazocine.

The synthesis, structure and catalytic properties of the [Mo7O24(μ-Mo8O26)Mo7O24]16− anion formed via two intermediate heptamolybdates [Co(en)3]2[NaMo7O24]Cl·nH2O and (H3O)[Co(en)3]2[Mo7O24]Cl·9H2O

Ageing a mixture of sodium molybdate, malonic acid, and tris(ethylenediamine)cobalt(iii) chloride yielded POMs.

From monomers to polymers: steric and supramolecular effects on dimensionality of coordination architectures of heteroleptic mercury(ii) halogenide–tetradentate Schiff base complexes

We report the synthesis and X-ray characterisation of six mercury(ii) halogenide–tetradentate Schiff base complexes.