C. Esteban-Calderón

Conformational and molecular study of the 4-(2-carboxyethyl)-1,2,3,4-tetrahydrocyclopent[b]indole

Abstract A conformational study of the title compound has been carried out in solution and solid states. The molecules are packed in the crystal forming a charge-transfer complex, where two different molecular pairs are found. Visible spectra data show two weak absorption bands.

Synthesis, characterization and crystal structure of the anilinium β-octamolybdate dihydrate

Abstract The anilinium β-octamolybdate dihydrate has been prepared in acidic aqueous solution. TG, DTG, IR and 1H NMR techniques have been used to identify the compound. It belongs to a series of molybdates of alkyl-N- and -N,N-substituted anilinium cations. Single crystals have been analyzed by X-ray diffraction. Crystal data are: (C6H8N)4[Mo8O26] · 2H2O, space group P 1 , Z = 1, a = 10.007(1), b = 8.014(2), c = 14.645(8)A, α = 109.81(3), β = 108.59(2), γ = 85.44(2)°, V = 1052.9(6) A3, Do = 2.49(1), Dx = 2.52 mg m−3, R = 0.026 and Rw = 0.031 for 5297 observed reflexions. The crystal structure consists of discrete [β-Mo8O26]4− polyanions, two crystallographically independent (C6H8N)+ cations and one independent water molecule. Polyanions are linked to the cations and to the water molecules by hydrogen bonds of types NH…O and OH…O.

Preparation and crystal data of isomorphous octamolybdates: crystal structure analysis of (3-MepyH)2(3-EtpyH)2[Mo8O26]

Abstract The preparation of a series of isomorphous β-octamolybdates of 3-methylpyridinium and 3-ethylpyridinium is reported along with their chemical characterization and crystal data. The compounds can be represented as (3-MepyH)x(3-EtpyH)4-x [Mo8O26], where 0

Molecular structure and reactivity of the 1,2-dihydrocarbazol-4(3H)-one: X-ray crystal structure of N-methyl and N-(p-methylbenzenesulfonyl) derivatives

Synthesis and reactivity analysis of the 1,2-dihydrocarbazol-4(3H)-one, and the N-methyl, N-tosyl and 2,2-dimethyl derivatives have been carried out. Molecular structures of the N-methyl and N-tosyl derivatives have been analyzed by X-ray diffraction. Crystals of the N-methyl derivative are monoclinic, space group P21/c,a=8.868(1),b=16.652(1),c=7.5440(4) Å, β=113.657(3). Crystals of the N-tosyl derivative are monoclinic, P21/c,a=12.0016(3),b=8.9178(2),c=16.0485(4) Å, β=104.372(2). An extended conjugation from the carbonyl group to the nitrogen atom and an envelope conformation for the common cyclohexenone fragment are evident in both cases. Oximation and Beckmann rearrangement, and etherification of the carbonyl group is reported.

Crystal structure and magnetic properties of linear chain potassium aquotetrafluoromanganate(III)

Abstract The crystal structure and single-crystal ac magnetic susceptibilities of KMnF 4 ·H 2 O are reported. The structure, which is isomorphous to that of RbMnF 4 ·H 2 O, consists of chains of alternating trans-[ MnF 4 F 2 2 ] 2− and trans-[ MnF 2 F 2 2 ( H 2 O ) 2 ] tetragonally elongated octahedra connected to each other by shared apical fluorine atoms. Crystal data: Space group C2 c , a = 13.907(1) A, b = 6.2136(2) A, c = 10.492(1)A, β = 104.69(1)°, V = 877.0(2) A 3 , D c = 2.85 g cm −3 , Z = 8, R = 0.044. Magnetic susceptibility measurements show a broad maximum around 52 K indicative of lower dimensionality behavior. The data may be fit to a Heisenberg S = 2 linear chain model with J k B = −6.5 K and g = 2.05. At 8.45 K a sharp peak in the susceptibility data parallel to the chains indicates weak ferromagnetic behavior.

Synthesis of 4-(N,N- dimethylaminoethyl)-1,2,3,4-tetrahydrocarbazole: molecular structure and reactivity of the 1,2-dihydrocarbazol-4(3H)-one and derivatives

The synthesis and reactivity of 1,2-dhydrocarbazol-4(3H)-one, (1), is reported. An X-ray molecular structure study of (1) provided information on the inactivity of its carbonyl group with potentially anionic reagents. 4(2- Dimethylaminoethyl)-1,2,3,4-tetrahydrocarbazole has been synthesized from 1,2,3,4-tetrahydrocarbazol-4-ylidenemethyl acetate by reduction of the exocyclic double bond, followed by transamination and reduction.

3-Hydroxy-4-nitro-6H-1,2,6-thiadiazine 1,1-dioxide: sodium and potassium salts

The title compounds form part of a series of S-dioxo analogs of pyrimidines which could act as potential antimetabolites. C 3H2 N 305 S. N a ÷ . H20 was refined to R = 0.041 using 1945 independent reflexions; monoclinic, space group P21/e with Z = 4, a = 6.2914 (3), b = 14.001 (1), c--8.9204 (3)/k, f l= 95.382 (4) °. The refinement for C3H2N3OsS-. K + . H20 led to R = 0.039 for 2006 reflexions; monoclinic, space group P21/e with Z = 4, a = 6.0744(4), b = 18.533(2), c = 7.497 (1)/k, fl = 91.68 (1) °. The anion, formed by deprotonation of the title compound, acts as a bidentate ligand for Na ÷ ions giving rise to two identical N a O bonds of 2.40/k. In the potassium salt, however, those K O distances are unequal, 2.88 and 3.17/k (10% elongated) and so the anion seems to behave as a monodentate ligand. The Na ÷ ions are octahedrally coordinated, with distances ranging from 2.34 to 2.49/k. The K ÷ ions are mainly surrounded by seven neighbours at distances in the range 2.78 to 3.01/k, forming a laterally capped trigonal prism. The observed N a O bond lengths agree with the expected distances for an interaction model of cation-dipole type. The observed K O distances are, however, elongated 7% with respect to the expected ones. These observations could be related to the different cationic changeability presented by these compounds. Strong electron modifications are found within the thiadiazine rings of these salts when compared with the free heterocyclic compound. Proton migration occurs within the thiadiazine rings during the formation of both salts. Dimeric anions are formed through two centrosymmetric hydrogen bonds.