Supramolecular assemblies in salts and co-crystals of imidazoles with dicarboxylic acids

Trivedi, Darshak R.; Ballabh, Amar; Dastidar, Parthasarathi

doi:10.1039/b309216j

Cited by 78 publications

(41 citation statements)

References 26 publications

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“…In this context, it may be noted that the crystal structure of the protonated 2-phenylimidazole (Hphim + ) is known. [27] Here the ψ value is 22.32°. Thus in all probability significantly different twisting of phim in 1 and 2 compared with that in Hphim + is due to the intramolecular C-H···π and C-H···Ni interactions observed in the present complex molecules.…”

Section: Description Of X-ray Structures and C-h···ni Interactionsmentioning

confidence: 99%

Intramolecular Apical C–H···M Interactions in Square‐Planar Nickel(II) Complexes with Dianionic Tridentate Ligands and 2‐Phenylimidazole

Mukhopadhyay

Pal

2006

Eur J Inorg Chem

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Keywords: Nickel(II) complexes / Square-planar complexes / Apical C-H···Ni interactions / X-ray structures / Theoretical calculations and sp 2 N-donor 2-phenylimidazole (phim) as the ancillary ligand have been synthesised and characterised by analytical, spectroscopic, magnetic and electrochemical methods. The solid-state structures of both complexes have been determined by X-ray crystallography. The asymmetric unit of 1 contains a single complex molecule while that of 2 contains four complex molecules with different conformations. The molecular structures of both complexes reveal that one of the two ortho C-H groups of the pendant phenyl ring of the phim ligand is very close to the metal centre at the apical site indicating the presence of an intramolecular C-H···Ni interaction. In the structures of 1 and 2, the shape of the C-H···Ni interaction is determined by the twisting of the phim ligand and the extent of orthogo- IntroductionThe long standing interest in the interaction of transition metal ions with proximate C-H fragments is primarily due to the C-H activation processes involved in many catalytic reactions. Such interactions have been scrutinised intensively for a better understanding of their structural and bonding features. [1][2][3][4][5][6][7][8][9][10][11][12] The C-H···M interaction in coordinatively unsaturated and electron-deficient (16-electron) species is called an agostic interaction or agostic bond where the filled C-H σ orbital interacts with an empty metal orbital. In these agostic interactions, generally the C-H fragment is side-on to the metal ion. This T-shape of the agostic C-H···M interaction facilitates the involvement of the filled metal dπ orbital and the empty C-H σ* orbital in back bonding. However, the nature of the apical C-H···M interactions in square-planar 16-electron complexes of d 8 metal ions is not very clear. [9][10][11][12] In such species, these interactions can be agostic bond (three-centre two-electron) as well as non-classical hydrogen bond (three-centre four-elec- [a]

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Section: Description Of X-ray Structures and C-h···ni Interactionsmentioning

confidence: 99%

Intramolecular Apical C–H···M Interactions in Square‐Planar Nickel(II) Complexes with Dianionic Tridentate Ligands and 2‐Phenylimidazole

Mukhopadhyay

Pal

2006

Eur J Inorg Chem

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“…An examination of the literature for structures having an azole interacting with a second molecule shows that the situation is relatively infrequent: supramolecular assemblies in salts and co-crystals of imidazoles with dicarboxylic acids have been reported [15] as well as cooperative association of pyrazoles and phenols [16].…”

Section: Introductionmentioning

confidence: 99%

Pyrazoles as molecular probes to study the properties of co-crystals by solid state NMR spectroscopy

et al. 2004

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Equimolar mixtures of 3,5-dimethylpyrazole (1) with four NH-imidazoles (2-5) have been studied by 13 C and 15 N CPMAS NMR and by DSC. In three cases, the solid mixture behaves as the sum of the individual components [imidazole (2), 2-methylimidazole (3) and 2,4(5)-dimethylimidazole (5)]. In one case [4,5-dimethylimidazole (4)], the mixture corresponds to a new species in which the dynamic behavior of 1 no longer exists.

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“…Rather than being aligned in the usual head-totail arrangement they assume a novel head-to-side configuration. As has been well documented in the articles by Macdonald and Iversen [25], Trivedi et al [26], Aakeroy and Hitchcock [30] and Aakeroy and Nieuwenhuyzen [31], the conventional head-to-tail arrangement has the donor COOH carboxylic group (tail) strongly hydrogen bonded to an acceptor carboxylate COO À group (head), creating infinite chains. In contrast, in the present material, the carboxylate COO À group of one anion is bonded to the side hydroxyl group COH of its neighbor.…”

Section: Crystal Structurementioning

confidence: 89%

“…Generally the mono-anions of dicarboxylic acids form hydrogen-bonded chains. The anions in these chains align head-to-tail with a carboxylic group (head) linked to [28][29][30][31][32][33]. We discuss in this contribution a striking exception to this general tendency, L-histidinium hydrogen malate.…”

Section: Introductionmentioning

confidence: 88%

“…Phenomenological rules describing the general tendencies of hydrogen-bonded building blocks or supramolecular synthons, as they are sometimes called in the literature, are now well established in crystal engineering where the groups led by Desiraju [1,17,24] and Aakeroy and Hitchcock [18], Aakeroy and Seddon [20], Aakeroy et al [22] have made decisive contributions. Recently, the concept has been extended to the particular case of co-crystals and salts between organic molecules and dicarboxylic acids [17][18][19][20][21][22][23][24][25][26][27]. Generally the mono-anions of dicarboxylic acids form hydrogen-bonded chains.…”

Section: Introductionmentioning

confidence: 99%

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Unusual supramolecular assembly and nonlinear optical properties of l-histidinium hydrogen malate

Gomes

Rodrigues

Costa

et al. 2006

Journal of Solid State Chemistry

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A new nonlinear optical material, L-histidinium hydrogen malate, has been synthesized. The crystal structure was determined at 90 K by single-crystal X-ray diffraction in order to analyze its supramolecular structure. A new building block type has been found. The malate anions form head-to-side infinite chains parallel to [100], via O-H?O interactions, instead of the usual head-to-tail infinite chains found in other hydrogen malate salts. The L-histidine cations form chains parallel to [100] via N-H?O hydrogen bonds, with cations of adjacent chains in anti-parallel way. The compound shows a good optical second-harmonic generation capability with an effective second-order susceptibility estimated to be 0.70 of that for potassium dihydrogen phosphate. r

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Supramolecular assemblies in salts and co-crystals of imidazoles with dicarboxylic acids

Cited by 78 publications

References 26 publications

Intramolecular Apical C–H···M Interactions in Square‐Planar Nickel(II) Complexes with Dianionic Tridentate Ligands and 2‐Phenylimidazole

Intramolecular Apical C–H···M Interactions in Square‐Planar Nickel(II) Complexes with Dianionic Tridentate Ligands and 2‐Phenylimidazole

Pyrazoles as molecular probes to study the properties of co-crystals by solid state NMR spectroscopy

Unusual supramolecular assembly and nonlinear optical properties of l-histidinium hydrogen malate

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