Hartree−Fock and Density Functional Methods and IR and NMR Spectroscopies in the Examination of Tautomerism and Features of Neutral 9-Acridinamine in Gaseous and Condensed Media

Rak, Janusz; Skurski, Piotr; Gutowski, Maciej; Jóźwiak, Ludwika; Błażejowski, Jerzy

doi:10.1021/jp961555c

Cited by 42 publications

(35 citation statements)

References 71 publications

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“…The ab initio methods of calculation, where geometry optimization is fulfilled in one approximation and the energy of a structure is calculated in another (in particular, at second order Möller Plesset level of theory), obviously slightly exaggerate the strength of H bonds in calix [4]arene; as a result, changes in H bond energy obtained by these methods approximate the value obtained by RHF/STO-2G. This tendency was also revealed in [25,26].…”

Section: Discussion Of Resultsmentioning

confidence: 88%

“…For compound I, RHF/PM3, RHF/STO-2G, RHF/3-21G, MP2/3-21G//RHF/3-21G (the latter performed by analogy with calculations by Rak, Skurski, Gutowski, et al [25]), RHF/6-31G, BLYP/3-21G, B3LYP/3-21G, B3LYP/6-31G, MP2/3-21G(d)/RHF/6-31G(d), and RHF/6-31G(d)/RHF/STO-2G mixed calculations (6-31G(d) for hydroxyl atoms, and STO-2G for the rest of the calixarene molecule) predicted the following values for variation of the hydrogen bond energy: 20.5 kcal/mole, 33.9 kcal/mole, 26.9 kcal/mole, 31.6 kcal/mole, 25.4 kcal/mole, 24.4 kcal/mole, 24.7 kcal/mole, 25.3 kcal/mole, 30.8 kcal/mole, and 24.8 kcal/mole, respectively. The deviation of these data from the value obtained by RHF/6-31G(d) (26.7 kcal/mole) is -6.2 kcal/mole, 7.2 kcal/mole, 0.2 kcal/mole, 4.9 kcal/mole, -1.3 kcal/mole, -2.3 kcal/mole, -2.0 kcal/mole, -1.4 kcal/mole, 4.1 kcal/mole, and -1.9 kcal/mole, respectively, or 23.2%, 27.0%, 0.8%, 18.4%, 4.9%, 8.6%, 7.5%, 5.2%, 15.4%, and 7.1%, respectively.…”

Section: Discussion Of Resultsmentioning

confidence: 99%

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Ab initio and density functional studies of cooperative hydrogen bonding in calix[4]-and calix[6]arenes

et al. 2006

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The cone conformation of 4 symmetry is shown by the Hartree-Fock method (3-21G basis) to be the predominant conformer of calix [4]arene; the compressed cone of 2 symmetry is the major conformer of calix [6] [7-9, 12, 13] and density functional [6-9, 14] methods, and only one work deals with investigation of calix [6]arenes by these methods [13]. None of these works dealing with calixarenes has reported on hydrogen bond energy calculations, although this energy is the key factor of conformational stability and conformational lability of calixarenes with free hydroxyl groups [12] and their reactivity [11].The stability of the hydrogen bond in calixarene was correlated with the reaction route involving this compound when dialkoxydihydroxycalix[4]arene was synthesized from monoalkoxytrihydroxycalix[4]arene [11] (Fig. 1). Similar alkylation and acylation reactions with intermediate phenoxide anions stabilized by the maximum number of stable hydrogen bonds were also reported for calixarenes having larger rings [11]. In his review [11] D. Rudkevich demonstrated in detail that intramolecular hydrogen bonds are as important as intermolecular hydrogen bonds for molecular void formation. Therefore further investigation of intramolecular hydrogen bonding in "guest-host" complexes (in particular, investigation of the energy parameters of hydrogen bonds) is of great importance in view of the influence of intramolecular hydrogen bonds on the route and rate of transformations involving cleavage and formation of covalent bonds and on the complexation ability of cavitands.I. I. Mechnikov Odessa National University; andrej_novikov@mail.ru, andrej_novikov@ukr.net.

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Section: Discussion Of Resultsmentioning

confidence: 88%

Section: Discussion Of Resultsmentioning

confidence: 99%

Ab initio and density functional studies of cooperative hydrogen bonding in calix[4]-and calix[6]arenes

et al. 2006

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“…In 10-methylacridinium chloride and bromide monohydrates, two water molecules are located between two halogen atoms and bind them through four intermolecular hydrogen bonds. The Cl···H (H 2 O) and Br···H (H 2 O) distances in both (1) and (2) are much shorter than those corresponding to contacts of the halogens with hydrogen atoms of the acridine moiety or the methyl group. This implies that water molecules are bonded more strongly with halogen anions than with 10-MeAcr + and one gains the impression that the complex anions [Cl·H 2 O] 2 2and [Br·H 2 O] 2 2exist in the solid phase.…”

Section: Resultsmentioning

confidence: 95%

Crystal structure and lattice energetics of 10-methylacridinium halides

Storoniak¹,

Krzymiński²,

Dokurno³

et al. 2000

Aust. J. Chem.

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The crystal structures of 10-methylacridinium chloride monohydrate, bromide monohydrate and iodide were determined by X-ray analysis. The compounds crystallize in the triclinic space group, P¯1, with 2 molecules in the unit cell. The molecular arrangement in the crystals revealed that hydrogen bonds (in hydrates) and van der Waals contacts play a significant part in intermolecular interactions. To discover their nature, contributions to the crystal lattice energy arising from electrostatic (the most important since the compounds form ionic crystals), dispersive and repulsive interactions were calculated. Enthalpies of formation of the salts, their stability and susceptibility to decomposition could be predicted from a combination of crystal lattice energies with values of other thermochemical characteristics obtained theoretically or taken from the literature. The role of water in the stabilization of the crystal lattice of the hydrates is also explained. The information gathered has given an insight into the features and behaviour of compounds which can be regarded as models of a large group of aromatic quaternary nitrogen salts.

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“…4 spectra have revealed that acridin-9amine can potentially exist in two tautomeric formsamino and imino-in equilibrium with each other (Scheme 1). In the past, some authors followed up this idea, 6−10 but others did not recognize it.…”

Section: Introductionmentioning

confidence: 99%

X-Ray, Quantum Mechanics and Density Functional Methods in the Examination of Structure and Tautomerism of N-Methyl-Substituted Acridin-9-amine Derivatives

Rak¹,

Krzymiński²,

Skurski³

et al. 1998

Aust. J. Chem.

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X-Ray diffraction has shown that N,N-dimethylacridin-9-amine (4) and N ,10-dimethylacridin-9-imine (5) both crystallize in the monoclinic space group P21/c (No. 14) with four molecules in the unit cell. The dimethylamino group in (4) is twisted through an angle of 58·6° relative to a nearly planar acridine moiety. On the other hand, the central ring in (5) is folded along the C(9) · · · N(10) axis through an angle of 26·3° and the exocyclic nitrogen atom with the methyl group attached to it is directed away from the concave side of the acridine nucleus. Theoretical ab initio Hartree–Fock (HF) and semiempirical (MNDO, AM1, PM3) quantum mechanics, as well as density functional (DFT) methods predicted that the N,N-dimethylacridin-9-amine molecule is planar within the acridine moiety and exhibits Cs symmetry, while the other four derivatives originating from the amino or imino tautomeric forms of acridin-9-amine do not have any symmetry elements. Molecules retaining the amino constitution are thermodynamically somewhat more stable than those arising from the imino form. The negative LUMO and HOMO energies, both predicted at the semiempirical level of theory and at the HF level in the latter case, imply that the relevant states are electronically stable. The comparable thermodynamic stabilities of both types of derivatives, as well as the fact that they can be synthesized, undoubtedly speak in favour of the existence of tautomeric phenomena in acridin-9-amine

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Hartree−Fock and Density Functional Methods and IR and NMR Spectroscopies in the Examination of Tautomerism and Features of Neutral 9-Acridinamine in Gaseous and Condensed Media

Cited by 42 publications

References 71 publications

Ab initio and density functional studies of cooperative hydrogen bonding in calix[4]-and calix[6]arenes

Ab initio and density functional studies of cooperative hydrogen bonding in calix[4]-and calix[6]arenes

Crystal structure and lattice energetics of 10-methylacridinium halides

X-Ray, Quantum Mechanics and Density Functional Methods in the Examination of Structure and Tautomerism of N-Methyl-Substituted Acridin-9-amine Derivatives

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