Yun-Cheng Cui

Solvothermal syntheses, structures, and luminescence of two heterometallic metal-organic frameworks constructed from m -BDC ( m -BDC = 1,3-benzene-dicarboxylate)

The reactions of m-H2BDC, NaOH with Cd(NO3)2 · 4H2O and Co(NO3)2 · 4H2O (m-BDC = 1,3-benzene-dicarboxylate) in DMF gave two isostructural three-dimensional (3D) heterometallic coordination polymers: [CdNa(m-BDC)2] · [NH2(CH3)2] (1) and [CoNa(m-BDC)2] · [NH2(CH3)2] (2), respectively. The compounds were characterized by single-crystal X-ray diffraction, X-ray powder diffraction, ICP, TGA, IR, and photoluminescence spectroscopy. The crystal structures were determined by X-ray diffraction and refined by full-matrix least-squares methods to R = 0.0221 and wR = 0.0579 using 1925 reflections with I > 2σ(I) for 1; and R = 0.0654 and wR = 0.1591 using 1881 reflections with I > 2σ(I) for 2. Their frameworks are constructed from M–O–C (M = Na, Cd and Co) chains composed of alternating six-coordinate Na(I) centers and four-coordinate Cd(II) or Co(II) centers. These chains are further linked by m-BDC to form unusual 3D open-framework structures.

An indium(III)-water chain based on an unusual acyclic water pentamer.

An in situ reaction under hydrothermal conditions leads to the formation of the title compound, diaqua(pyridine-2-carboxylato)(pyridine-2,6-dicarboxylato)indium(II) trihydrate, [In(C 6 -H 4 NO 2 )(C 7 H 3 NO 4 )(H 2 O) 2 ]·3H 2 O, in which the central In III atom is seven-coordinated by one pyridine-2,6-dicarboxylate ligand, one pyridine-2-carboxylate ligand and two water molecules in a pentagonal-bipyramidal coordination environment. An indium(III)-water chain based on an unusual water pentamer is observed.

Disodium calcium dinickel(II) bis-[diphosphate(V)] deca-hydrate.

In the title compound, Na2CaNi2(P2O7)2(H2O)10, there are two distinct P-atom sites, each tetrahedrally coordinated by four O atoms. The resulting phosphate tetrahedra link through a common O atom, forming a [P2O7]4− diphosphate unit. The Ni—O coordination is square pyramidal with four O atoms from two diphosphate groups in equatorial positions and the vertex occupied by a water O atom. The (P2O7)(H2O) units link the Ni atoms, forming a chain of pyramids and tetrahedra. As a result of the d-glide and twofold-axis symmetry of space group Fdd2, the chains propagate along [101] and [10], and chains in adjacent layers are mutually orthogonal. The Ca cation, located on a rotation axis, and the Na cation are each octahedrally coordinated by four O atoms and two waters. The Ni-chain arrangement is stabilized by Ca and Na coordination and a network of O—H⋯O hydrogen bonds.