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A new spin crossover coordination polymer (SCO-CPs) of Fe(II)-4,4′-bipyridine (4,4′-bipy) family: {Fe(4,4′-bipy) 2 (H 2 O) 2 }·(4,4′-bipy)· 8(H 2 O)·2(ClO 4 ) ( 3 ), which displays half spin transitions between 100 and 300 K, has been synthesized and structurally characterized. Compound 3 featured with two-dimensional (2-D) grids connected by hydrogen bonds and π … π packing between one-dimensional (1-D) chains, the 2-D grids expand to three-dimensional (3-D) architecture supported by a “S-shaped holder” involving lattice 4-4′-bipy, water molecules and perchlorate anion. We compared 3 with the other two analogous complexes: ({Fe(4,4′-bipy) (H 2 O) 2 (NCS) 2 }·4,4′-bipy, 1 and {Fe(4,4′-bipy) 2 (NCS) 2 }·mSolv, 2 ) through Hirshfeld surfaces analysis, which revealed that the low ligand field strength (NCS − ) and lone-pair…H contacts contribute to the stabilization of HS (high-spin) state of the Fe(II) ion, while the high ligand field strength (4,4′-bipy) and strong intermolecular contacts (hydrogen bonds and π … π packing interactions) make for the LS (low-spin) state. [ABSTRACT FROM AUTHOR]

Highlights: [•] Two copper complexes derived from polypyridine and salicylide ligands have been prepared. [•] Intermolecular interactions in them have been investigated by using Hirshfeld surfaces. [•] These two complexes can intercalation with DNA. [ABSTRACT FROM AUTHOR]

Highlights: [•] Two new complexes from 6-methylnicotinic acid (6-MNA) have been presented. [•] Influences of metals on 6-MNA through Hirsheld surfaces have been investigated. [•] Intermolecular interactions of complexes have been quantificationally visualized. [ABSTRACT FROM AUTHOR]

The complex [Cu2(μ-L)2]. DMF (L = 2, 2'-[1-(2, 4, 6-trichlorophenyl)-1H-1, 2, 4-triazole-3, 5-diyl] diphenolate) has been prepared and its structure determined. The two CuII ions are four-coordinated in a planar structure, with the DMF molecule wrapped in the 'wings' of ligand L. Hirshfeld surface and fingerprint plots reveal that the complex structure is stabilised mainly by H···H, C-H ... Cl, C-H···π,π···π and lone-pair···π (C-Cl) intermolecular interactions. [ABSTRACT FROM AUTHOR]

Two new mononuclear iron (II) coordination complexes: Fe(L1)2(SCN)2(1, L1:5-dimethylether-4-(4-methylphenyl)-3-(2-pyridinyl)-1,2,4-triazole) and Fe(L2)3(ClO4)2(2, L2:1-ethyl acetate-2-(2-pyridinyl)-imidazole), for the exploration of spin-crossover compounds have been synthesized and characterized. Structural analysis revealed that the framework of complex1is featured with 1-D chain structure connected by weak π···π interactions between the adjacent L1ligands, while complex2featured with various kinds of weak intermolecular hydrogen bonding interactions between Fe(L2)32+cation and ClO4−anion, which lead to a close crystal packing. The intermolecular interactions have shown a significant influence on the physical properties, and magnetic measurements of complexes1and2in the solid state at the room temperature revealed that the weak intermolecular interactions in1resulted in HS (high-spin) state, while the strong interactions in2lead to LS (low-spin) state over the whole temperature range. [ABSTRACT FROM AUTHOR]

Two zinc (II) pseudo-halide complexes [Zn( L 1 )(N 3 ) 2 ] n ( 1 L 1 : 1,2-diaminocyclohexane) and Zn( L 2 ) 2 (N 3 ) 2 ( 2 L 2 : 4,5-dimethy-2-(pyridine-2-yl) imidazole) have been synthesized and characterized. Single-crystal X-ray structural analysis revealed that the central Zn II atoms in 1 displays distorted trigonal bipyramidal arrangement with a 1D chain structure bridged by N 3 − anions, while in 2 , the central Zn II atoms incorporating with two bidentate L 2 ligands, and adopts an octahedral geometry and shows a “butterfly” coordination framework. Structural analysis demonstrated that the organic ligands play an important role in determining the resultant structure. In addition, both complexes were further characterized by thermal stability properties and Hirshfeld surface analysis. [ABSTRACT FROM AUTHOR]

By using the ligands 4-(4-bromobenzylideneamino)-4H-1,2,4-triazole (L1) and 4-(4-iodobenzylideneamino)-4H-1,2,4-triazole (L2), four different organic salts HL1+·Cl− (1), L1·HL1+·ClO4− (2), HL2+·Cl− (3), and L2·HL2+·ClO4− (4) have been synthesized and structurally characterized through single-crystal X-ray diffraction (L1, L2, 2 and 3) and PXRD (1 and 4) measurements. The results revealed that ligands L1 and L2 themselves exhibit a polymeric 1-D chain in a zigzag structure connected by C–Br…N and C–I…N halogen-bonding contacts, respectively. L1 in salt 2 was connected into a 3-D structure through N–H…O hydrogen-bonding contacts, while the interleaved 3-D network of L2 in salt 3 was mainly connected by C–I…Cl halogen-bonding contacts. As a result, the fluorescence properties of ligands L1 and L2 were reserved in halogen-bonding connected salts 1 and 3, while there was a reduction in hydrogen-bonding connected salts 2 and 4. Thus, the relationship between emission properties and halogen-bonding contacts can be proposed. [ABSTRACT FROM AUTHOR]