Very long C–H···O contacts can be weak hydrogen bonds: experimental evidence from crystalline [Cr(CO)3{η6-[7-exo-(CCH)C7H7]}]

Steiner, Thomas; Lutz, Bert; Maas, John van der; Schreurs, Antoine M. M.; Kroon, Jan; Tamm, Matthias

doi:10.1039/a706980d

Cited by 44 publications

(22 citation statements)

References 5 publications

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“…Although it is remarkable that there are so many contacts, and so many of different type, the interactions themselves are consistent with known guidelines for hydrogen bond formation [22,23]. In these two cases molecular recognition of the hydrogen bonds leads to aggregation and a supramolecular assembly of infinite two-dimensional network.…”

Section: Five-coordinated Zinc(ii) Complexes-description Of the Crystmentioning

confidence: 56%

Zinc(II) complexes derived from pyridine-2-carbaldehyde thiosemicarbazone and (1E)-1-pyridin-2-ylethan-1-one thiosemicarbazone. Synthesis, crystal structures and antiproliferative activity of zinc(II) complexes

Kovala‐Demertzi

Yadav

Wiecek

et al. 2006

Journal of Inorganic Biochemistry

116

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Section: Five-coordinated Zinc(ii) Complexes-description Of the Crystmentioning

confidence: 56%

Zinc(II) complexes derived from pyridine-2-carbaldehyde thiosemicarbazone and (1E)-1-pyridin-2-ylethan-1-one thiosemicarbazone. Synthesis, crystal structures and antiproliferative activity of zinc(II) complexes

Kovala‐Demertzi

Yadav

Wiecek

et al. 2006

Journal of Inorganic Biochemistry

116

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“…Distances of about 2.5 Å between the hydrogen and oxygen or nitrogen atoms in these structures are indicative of weak hydrogen bonding [19,[21][22][23][24]. The structure represented in Fig.…”

Section: Models and Computational Detailsmentioning

confidence: 99%

The axial coordination in subphthalocyanines: Geometrical and electronic aspects

Ferro

Vega

Claessens

et al. 2001

J. Porphyrins Phthalocyanines

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Theoretical calculations were performed for studying the electronic molecular structure of axial subphthalocyanine (SubPc) derivatives. The intermolecular SubPc interactions were also investigated at theoretical level using adequate models. These models represent the interaction of one Cl(OR)-SubPc with the surrounding molecules through the Cl atom as well as the interaction of the Cl-SubPc with an incoming diiminoisoindole group in the first steps of the open ring reaction. The SubPc complexes with more electronegative atoms than Cl heteroatoms in apical positions are more pyramidal than Cl-SubPc. The B-X and B-Np are the most sensitive macrocycle positions with respect to the axial substitutions in SubPcs. The B-X bond has an elevated polarity and seems to correlate with the chemical reactivity of these compounds. The theoretical calculations of the near-frontier orbitals reveal an outstanding energetic and structural homogeneity along the studied series which is in correspondence with the fact that the axial ligand has only a small influence on the position of the maximum bands in UV-vis spectra as well as in the first half-wave potentials for oxidative processes. The study of the intermolecular interactions give information about their influence on the molecular structure of the axial complexes of the SubPcs. The characterization of the interaction of one Cl-SubPc with a pyrrol containing group may be useful in the understanding of the mechanism of the ring expansion reactions. In general, the present results indicate that the apical position may be a critical reactive center both for redox and axial substitution processes.

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“…The shortest O/H distance is about 2.6 Å which permit to classify this interaction also as a weak hydrogen bond, using the same criterion used for the earlier case. The features of weak hydrogen bonds and the criteria used to classify them have been extensively discussed very recently by many authors [46][47][48][49][50][51][52][53][54][55][56][57] and have already been used by us in previous works. 12,14 It is important to recall that hydrogen bonds are additive interactions 45 and, because of this characteristic, even weak hydrogen bonds can play an important role in stabilising the structure of a material.…”

Section: Radial Correlation Function and The Liquid Structurementioning

confidence: 99%

“…These results indicate that the weak hydrogen bonds between the carbonylic oxygen and hydrogen play a important role in the stabilisation of the liquid structure, what agrees with a great number of other results previously published. [41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57] Besides, the relative position of one molecule with respect to an other, due to the correlation between the oxygen and the methyl hydrogens, could be interpreted as more a indication of the weight of the weak hydrogen bonds in the structure. Taking this result into account one can suppose that this type of interaction can play an important role in the structure of molecules like proteins for example, mainly if normal hydrogen bonds are not involved.…”

Section: Radial Correlation Function and The Liquid Structurementioning

confidence: 99%

Structure and weak hydrogen bonds in liquid acetaldehyde

Cordeiro¹,

Cordeiro²

2004

J. Braz. Chem. Soc.

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Investigaram-se a estrutura e formação de pontes de hidrogênio no acetaldeído líquido por simulações de Monte Carlo. Um modelo para acetaldeído com todos os átomos explicitados foi otimizado no presente trabalho. Os valores teóricos obtidos para a entalpia de vaporização e a densidade do líquido mostram boa concordância com os dados experimentais. Os gráficos de função de distribuição radial (rdf) indicam um líquido bem estruturado comparado com outros líquidos orgânicos dipolares semelhantes. A minimização usando mecânica molecular em fase gasosa produz um trímero com uma estrutura muito estável. A geometria deste complexo apresenta boa concordância com os gráficos de rdf. A correlação sítio-sítio mais próxima observada é entre o oxigênio e o hidrogênio da carbonila, sugerindo que esta correlação possui um importante papel na estrutura do líquido e suas propriedades. A distância média O⋅⋅⋅H e o ângulo C-H⋅⋅⋅O obtidos são característicos de pontes de hidrogênio fracas.Monte Carlo simulations have been performed to investigate the structure and hydrogen bonds formation in liquid acetaldehyde. An all atom model for the acetaldehyde have been optimized in the present work. Theoretical values obtained for heat of vaporisation and density of the liquid are in good agreement with experimental data. Graphics of radial distribution function indicate a well structured liquid compared to other similar dipolar organic liquids. Molecular mechanics minimization in gas phase leads to a trimer of very stable structure. The geometry of this complex is in very good agreement with the rdf. The shortest site-site correlation is between oxygen and the carbonyl hydrogen, suggesting that this correlation play a important role in the liquid structure and properties. The O⋅⋅⋅H average distance and the C-H⋅⋅⋅O angle obtained are characteristic of weak hydrogen bonds. Keywords:Monte Carlo simulation, acetaldehyde, liquid structure, weak hydrogen bond IntroductionIn recent years, theoretical investigation of liquid state properties has become a challenging subject for theoretical chemists and physicists, since fast and high memory capability computers have become available at relatively low cost.1-3 The development of suitable computer simulation methods have made it feasible to investigate a great number of liquid state properties that would not be possible, or difficult to access, with other theoretic or experimental techniques. 4,5 However, the success of the investigations using computational methodologies depends strongly on the availability of potential functions capable of describing the intermolecular interactions adequately.6-9 Therefore, the optimisation of meaningful intermolecular potential functions is of fundamental importance for the investigation of liquid state properties using theoretical methods. This optimisation is not simple, however, due to the complexity of the liquid intermolecular interactions, and some criteria, such as pairwise additivity and consideration of dipolar interaction exclusively, have been used to s...

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Very long C–H···O contacts can be weak hydrogen bonds: experimental evidence from crystalline [Cr(CO)3{η6-[7-exo-(CCH)C7H7]}]

Cited by 44 publications

References 5 publications

Zinc(II) complexes derived from pyridine-2-carbaldehyde thiosemicarbazone and (1E)-1-pyridin-2-ylethan-1-one thiosemicarbazone. Synthesis, crystal structures and antiproliferative activity of zinc(II) complexes

Zinc(II) complexes derived from pyridine-2-carbaldehyde thiosemicarbazone and (1E)-1-pyridin-2-ylethan-1-one thiosemicarbazone. Synthesis, crystal structures and antiproliferative activity of zinc(II) complexes

The axial coordination in subphthalocyanines: Geometrical and electronic aspects

Structure and weak hydrogen bonds in liquid acetaldehyde

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