Um estudo teórico de propriedades moleculares em complexos de hidrogênio trimoleculares C2H4···2HF, C2H2···2HF e C3h6···2HF

Oliveira, Boaz G.; Araújo, Regiane C. M. U.; Pereira, Flávia S.; Lima, Emmanuela Ferreira de; Silva, Washington L. V.; Carvalho, Antônio B.; Ramos, Mozart N.

doi:10.1590/s0100-40422008000700014

Cited by 25 publications

(8 citation statements)

References 16 publications

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“…In other words, the electronic structure of the σ-hole is preserved as well as H (HOX) is not important as expected, no matter whether Table 5. Initially, the -G/U values in the range of 1.132-1.349 testify the non-covalent characters of the I-VI complexes [87][88][89]. Once the electronic density potential operator is outweighed by the kinetic followed by the low electronic density amounts and positive Laplacian values, certainly the I-VI complexes are weakly bound, just like has been demonstrated throughout this work.…”

Section: Fig 4 Mep Fields Of H 3 Sih and Hof Monomers As Well As Of supporting

confidence: 55%

The electronic mechanism ruling the dihydrogen bonds and halogen bonds in weakly bound systems of H3SiH···HOX and H3SiH···XOH (X = F, Cl, and Br)

et al. 2015

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The dihydrogen bond complexes (H 3 SiH•••HOX) and halogen bond complexes (H 3 SiH•••XOH) formed between SiH 4 and hypohalous acids HOX (X = F, Cl, and Br) have been studied at the MP2/6-311++G(2d,2p) computational level. The analyses of structure and infrared vibration frequencies have revealed tendencies in the red shifts and blue shifts of the stretch frequencies of the Si-H, H-O, and O-X bonds. Besides the computation of the interaction energies, punctual atomic charges and charge transference amounts were determined at light of the Natural Bond Orbital (NBO) approach, by which the quantifications of the s-and p-characters of hydrogen, oxygen, and silicon also were useful to unveil the frequency shifts aforementioned. With the purpose to elucidate the donor/acceptor interface along the charge transfer mechanism between the dihydrogen bonds and halogen bonds, the application of the hierarchical cluster analysis (HCA) and principal component analysis (PCA) chemometric techniques were useful in this regard. Moreover, the interaction strengths of the H 3 SiH•••HOX and H 3 SiH•••XOH complexes was computed through a model that embodies the frequency shifts and topological parameters derived from quantum theory of atoms in molecules (QTAIM).

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Section: Fig 4 Mep Fields Of H 3 Sih and Hof Monomers As Well As Of supporting

confidence: 55%

The electronic mechanism ruling the dihydrogen bonds and halogen bonds in weakly bound systems of H3SiH···HOX and H3SiH···XOH (X = F, Cl, and Br)

et al. 2015

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“…On the other hand, it has also been reported that binary hydrogen complexes are not dominant structures, since ternary complexes are also important for a thorough analysis of reaction mechanisms [26]. In practice, it is well known that ternary complexes are more stable than binary ones because stronger or multiple hydrogen bonds [27] as well as dihydrogen bonds [28][29][30] are formed, as reported by Jursic [31], Grabowski [32,33], Biczysko and Latajka [34], and others [35,36].…”

Section: Introductionmentioning

confidence: 94%

Theoretical aspects of binary and ternary complexes of aziridine⋯ammonia ruled by hydrogen bond strength

Oliveira

Araújo

2011

J Mol Model

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B3LYP calculations, ChelpG atomic charges, and quantum theory of atoms in molecules (QTAIM) integrations were used to investigate the binary (1:1) and ternary (1:2) hydrogen-bonded complexes formed by aziridine (1) and ammonia (2). In a series of analysis, geometry data, electronic parameters, vibrational oscillators, and topological descriptors were used to evaluate hydrogen bond strength, and additionally to determine the more prominent molecular deformations upon the formation of C(2)H(5)N···NH(3) (1:1) and C(2)H(5)N···2NH(3) (1:2) systems. Taking a spectroscopic viewpoint, results obtained from analysis of the harmonic infrared spectrum were examined. From these, new vibrational modes and red- and blue-shifts related to the stretch frequencies of either donors or acceptors of protons were identified. Furthermore, the molecular topology of the electronic density modeled in accord with QTAIM was absolutely critical in defining bond critical points (BCP) and ring critical points (RCP) on the heterocyclic structures. Taking all the results together allowed us to identify and characterize all the N···H hydrogen bonds, as well as the strain ring of the aziridine and its stability.

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“…for q (MEP) H -d reflects concentration of atomic charge only in H -d of the (c) complex, what is a qualitative justification for the blue-shift of ?23.6 cm -1 on (Be-H -d ) bond. Based on recent results, it was demonstrated that the electronic density computed at light of QTAIM protocol can be used to estimate the variation on stretching frequencies of p hydrogen-bonded complexes, in special, the red-shifts effects of their proton donors [66]. In Fig.…”

Section: Qtaim Molecular Topology and Charge Transfermentioning

confidence: 99%

A theoretical study of three and four proton donors on linear HX···BeH2···HX and bifurcate BeH2···2HX trimolecular dihydrogen-bonded complexes with X = CN and NC

et al. 2009

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The interaction phenomenon H -d ÁÁÁH ?d between two hydrogen atoms binding each other is well-known in dihydrogen-bonded complexes. Either by experimental or theoretical viewpoint, dihydrogen bonds are often known as directional or bifurcate interactions. Regarding the beryllium hydride BeH 2 , its capacity to form bimolecular complexes with proton donors has been demonstrated, but in some cases, trimolecular complexes are also characterized in a minimum of the potential energy surface. As such, in this work is presented a theoretical study about the formation of trimolecular dihydrogen complexes with three hydrogen centers. By taking into account the beryllium hydride BeH 2 as proton acceptor, two classical proton donors were chosen, HCN and HNC. The great goal of this work is the analysis of two dihydrogen complexes types: bifurcate BeH 2 ÁÁÁ2HX and linear HXÁÁÁBeH 2 ÁÁÁHX. In these systems, it is discussed the capacity of one hydride H -d (H-Be-H -d ) to interact simultaneously with two proton donors, as well as when two hydrides H -d ( -d H-Be-H -d ) form linear dihydrogen bonds. In this context, the analysis of the vibrational harmonic spectrum at B3LYP/6-311 ??G(3d,3p) level of theory and the interpretation of the topological parameters derived from Quantum Theory of Atoms in Molecules (QTAIM) aided us to determine which is the most stable trimolecular complex, either bifurcate or linear. Moreover, quantification of charge transfer measured by the QTAIM formalism as well as by ChelpG calculations also were used with the purpose to justify infrared effects, such as red-shift and blue-shift stretch modes on donors (HCN and HNC) and acceptors (BeH 2 ) of protons.

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Um estudo teórico de propriedades moleculares em complexos de hidrogênio trimoleculares C2H4···2HF, C2H2···2HF e C3h6···2HF

Cited by 25 publications

References 16 publications

The electronic mechanism ruling the dihydrogen bonds and halogen bonds in weakly bound systems of H3SiH···HOX and H3SiH···XOH (X = F, Cl, and Br)

The electronic mechanism ruling the dihydrogen bonds and halogen bonds in weakly bound systems of H3SiH···HOX and H3SiH···XOH (X = F, Cl, and Br)

Theoretical aspects of binary and ternary complexes of aziridine⋯ammonia ruled by hydrogen bond strength

A theoretical study of three and four proton donors on linear HX···BeH2···HX and bifurcate BeH2···2HX trimolecular dihydrogen-bonded complexes with X = CN and NC

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