Crystallises In P2 Research Articles

Characterization of Molecular Complexes of 1,4-Naphthoquinone Derivatives

The structures of sulphur atom tethered quinone containing flexible carboxylic acid (3-methyl-1,4-dioxo-1,4-dihydronaphthalen-2-ylsulfanyl)acetic acid (1) and its molecular complex with 4,4′-bipyridine (3) are determined. The compound 1 crystallizes in P-1 (triclinic, a = 7.5378(6) A, b = 7.6413(7) A, c = 10.3101(9) A; α = 89.779 (7)°, β = 81.042 (5)°, γ = 89.101(7)°) and the molecular complex 3 crystallises in P2(1)/n (monoclinic, a = 9.3383(7) A, b = 3.970(3) A, c = 42.130(3) A, β = 91.056(5)°) space groups, respectively. The R 2 2 (8) type hydrogen bonding between dicarboxylic acid groups present in the parent compound 1 is lost on interaction with 4, 4′-bipyridine; in the molecular complex 3 R 2 2 (7) type of O···H–C and O–H···N interactions are present between the pyridine rings and carboxylic acid groups. The molecular complex (4) derived from 3-carboxymethylsulfanyl-1,4-dihydroxynaphthalen-2-yl-sulfanyl) acetic acid (2) with triphenylphosphine oxide in 1:2 ratio, crystallises in C2/c space group have monoclinic, a = 26.0494(13) A, b = 10.5402(5) A, c = 17.1023(8) A, β = 108.719 (5)°). The triphenylphosphine oxide molecules are preferentially held by O–H···O interactions between carboxylic acid and P=O bond. The structures of (3-methyl-1,4-dioxo-1,4-dihydronaphthalen-2-ylsulfanyl) acetic acid , its molecular complex with 4,4′-bipyridine and molecular complex of 3-carboxymethylsulfanyl-1,4-dihydroxy naphthalen-2-yl-sulfanyl)acetic acid with triphenylphosphine oxide are presented

All -cis-1,2,3,4,5,6-cyclohexanehexacarboxylate two-dimensional gadolinium(III) complexes: Synthesis, X-ray crystal structure and magnetic properties

The first gadolinium(III) complexes with the trideprotonated form of the 1,2,3,4,5,6-cyclohexanehexacarboxylic acid (H 3clhex 3−) of formulae [Gd(H 3clhex)(H 2O) 4] n ·3nH 2O ( 1) and [Gd(H 3clhex)(H 2O) 4] n ·6nH 2O ( 2) have been prepared through the gel technique and their structures determined by single crystal X-ray diffraction. The structure of 1 is made up of 6 3 honey-comb layers which are generated by [Gd(H 2O) 4] 3+ cations and H 3clhex 3− anions acting as three-fold nodes and three-fold connectors, respectively. The structure of 2 consists of a [4 4,6 2] two-dimensional network extended in the ac plane where the H 3clhex −3 groups act as four-fold connectors and the [Gd(H 2O) 4] 3+ units as four-fold nodes. Compound 1 crystallises in a non-centrosymmetric space group P2 1. Its absolute structure could be determined reliably, indicating the spontaneous resolution of a homochiral crystal and the freezing of one of the conformations of the all- cis H 3clhex −3 ligand. Compound 2 crystallises in the P2 1/ n space group, the presence of an inversion centre making both conformations to occur. 1 and 2 are different solvates of the same system, the latter one synthesised under a higher pH value of the gel than the former. The investigation of the magnetic properties of 1 and 2 in the temperature range 1.9–300 K reveals a Curie law behaviour for the two compounds.

Design, synthesis, structural and thermal characterisation of polymeric chlorocadmate(II) compounds with one-dimensional inorganic chain structures

The chlorocadmate(II) compounds of formula (Hmepd) [CdCl 3] ( 1) (Hmepd = 1-methylpiperidine cation). (H 2meen) 2[Cd 2Cl 8] ∗d H 2O ( 2) (H 2meen = N-methylethylenediamine dication) and (H 2amepz) [Cd 2Cl 6(H 2O) 2] ( 3) (H 2amepz = 1-amino-4-methylpiperazine dication) are synthesised and their structural and thermal properties investigated. Compound 1 crystallises in space group P2/ a. The unit cell dimensions are a = 15.046(2), b = 10.408(2) and c = 6.786(3) A ̊ , β = 92.39(2)°, Z = 4 . The final R value is 0.0353 ( Rw = 0.0328). Its structure consists of one-dimensional polymeric chains of face-sharing CdCl 6 octahedra running along the c axis and methylpiperidinium cations. Compound 2 crystallises in the C2/ a space group. The unit cell dimensions are a = 18.459(2), b = 6.986(3) and c = 18.167(2) A ̊ , β = 115.95(2)°, Z = 4 . The final R value is 0.0296 ( Rw = 0.0330). Its crystal structure consists of polymeric chains of [CdCl 4] 2− anions running along the b axis, organic cations and non-coordinated water molecules. Compound 3 crystallises in the P2/ a space group, with a = 7.542(2), b = 14.568(4) and c = 8.052(2) A ̊ , β = 106.91(3)°, Z = 2. . The final R value is 0.330 ( Rw = 0.340). The crystal structure consists of organic cations and polymeric chains of edge-sharing CdCl 5(H 2O) octahedra. In compounds 1 and 2 hydrogen bond interactions between the inorganic chains, the organic cations and the water molecules, if present, contribute to the crystal packing, while in compound 3 this contribution comes from the contact less than 3.5 Å. The thermal characterisation is also discussed. The structures are composed with other examples of chlorocadmate(II) compounds.