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1.
Acta Crystallogr C ; 58(Pt 12): o721-3, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12466625

RESUMO

In the title compound, C(15)H(17)NO(2), the ethoxycarbonyl group is anti with respect to the pyrrole N atom. The angle between the planes of the phenyl and pyrrole rings is 48.26 (9) degrees. The molecules are joined into dimeric units by a strong hydrogen bonds between pyrrole N-H groups and carbonyl O atoms. The geometry of the isolated molecule was studied by ab initio quantum mechanical calculations, employing both molecular orbital Hartree-Fock (MO-HF) and density functional theory (DFT) methods. The minimum energy was achieved for a conformation where the angle between the planes of the phenyl and pyrrole rings is larger, and that between the ethoxycarbonyl and pyrrole planes is smaller than in the solid-state molecule.

2.
Acta Crystallogr C ; 58(Pt 11): o685-7, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12415183

RESUMO

In the title compound, C(16)H(17)NO(3).H(2)O, the pyrrole ring is distorted slightly from ideal C(2v) symmetry. Three strong hydrogen bonds link the substituted pyrrole and water molecules to form infinite chains, in which the hydrogen bonds form rings and chain patterns. Two intermolecular C-H.pi interactions maintain the internal cohesion between these chains. The molecular structure differs slightly from that of the isolated molecule calculated by ab initio quantum-mechanical calculations. In the latter model, the non-H substituent atoms share the plane of the pyrrole ring, except for the phenyl group, which lies almost perpendicular to this plane.

3.
Acta Crystallogr C ; 58(Pt 9): o572-4, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12205393

RESUMO

The title compound, C(21)H(37)NO(2), is a new amphiphilic pyrrole with a long hydrocarbon chain, which will be used as a precursor for the synthesis of Langmuir-Blodgett films of porphyrins. Molecules related by an inversion centre are joined head-to-head into dimers by strong N-H.O hydrogen bonds. The dimers pack in the structure with their carbon chains parallel to one another, thereby forming alternating layers of carbon chains and pyrrole heads. The structure is further stabilized by two weak C-H.pi intermolecular interactions, thereby saturating the hydrogen-bonding capability of the aromatic pi-electron clouds.

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