Resonance and solvent effects on absorption spectra of some 2- and 4-( - M)-substituted aniline derivatives

1983 ◽  
Vol 36 (4) ◽  
pp. 701 ◽  
Author(s):  
T Yokoyama ◽  
RW Taft ◽  
MJ Kamlet
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Spectral Data ◽  
Absorption Spectra ◽  
Solvent Effects ◽  
Hydrogen Bond Donor ◽  
Intermolecular Hydrogen Bonds ◽  
Hydrogen Bond Acceptor ◽  
Aniline Derivatives ◽  
Hydrogen Bonded

The N-H protons of N-methyl-2-X-aniline derivatives remain intramolecularly hydrogen bonded in HBA (hydrogen bond acceptor) solvents where X = COOMe and NO2, but form intermolecular hydrogen bonds to the HBA solvents where X = CN. The order of response of vmax to solvent HBA basicity for the Cl → C2 bands of N-unsubstituted-2-(-M)-substituted aniline derivatives and the Cl → C4 bands of 4-(-M)-substituted aniline derivatives follows the orders of the hydrogen bond donor acidities of the amine protons, which are determined primarily by the mesomeric effects of the 2- and 4-substituents. The spectral data indicate that intramolecularly hydrogen bonded 2-(-M)-substituted aniline derivatives are near sp2 hybridized in non-HBA solvents and, unlike several 4-substitute anilines, do not undergo significant rehybridization in HBA solvents. Bath ochromic shifts resulting from hydrogen bonds by corresponding 2- and 4-substituted aniline derivatives to HBA solvents are of similar magnitudes.

Resonance and solvent effects on absorption spectra of 2-nitroaniline derivatives

1976 ◽  
Vol 29 (7) ◽  
pp. 1469 ◽  
Author(s):  
T Yokoyama
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Spectral Data ◽  
Absorption Spectra ◽  
Long Range ◽  
Solvent Effects ◽  
Intramolecular Hydrogen Bonding ◽  
Intramolecular Hydrogen

Spectral data for N-methyl-2-nitroaniline correlate well with those for N,N-dimethyl-2-nitroaniline in non-hydrogen-bonding, hydrogen-bond-accepting and amphiprotic alcoholic solvents. This same pattern has been reported for N-methyl-2-nitro-p-toluidine. These results indicate that these N-methyl compounds have no hydrogen bonds with any of the solvents studied and intramolecular hydrogen bonding predominates. In the N.M.R. spectra of such amines, long-range coupling between the H5 (ring) and N-H protons is not necessarily evidence for intramolecular hydrogen bonding.� +M substituents at the 4-position increase the twist of the dimethylamino and 2-nitro groups and enhance the C1 → C2 transition, an effect which follows the order of +M abilities of the 4-substituents.

6,9-Dibromo-2a,10b-diphenyl-2a,5,10,10b-tetrahydro-2H,3H-2,3,4a,10a-tetraazabenzo[g]cyclopenta[cd]azulene-1,4-dione monohydrate

2006 ◽  
Vol 62 (5) ◽  
pp. o1754-o1755
Author(s):  
Neng-Fang She ◽  
Sheng-Li Hu ◽  
Hui-Zhen Guo ◽  
An-Xin Wu
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Water Molecule ◽  
Title Compound ◽  
Supramolecular Structure ◽  
Hydrogen Bond Donor ◽  
Hydrogen Bond Acceptor ◽  
Compound C ◽  
Bifurcated Hydrogen Bond

The title compound, C24H18Br2N4O2·H2O, forms a supramolecular structure via N—H...O, O—H...O and C—H...O hydrogen bonds. In the crystal structure, the water molecule serves as a bifurcated hydrogen-bond acceptor and as a hydrogen-bond donor.

Two polymorphs and the diethylammonium salt of the barbiturate eldoral

2012 ◽  
Vol 68 (2) ◽  
pp. o65-o70 ◽  
Author(s):  
Thomas Gelbrich ◽  
Denise Rossi ◽  
Ulrich J. Griesser
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Barbituric Acid ◽  
Layer Structure ◽  
Chain Structure ◽  
Hydrogen Bond Acceptor ◽  
Layer Structures ◽  
A Chain ◽  
Derivatives Of ◽  
Hydrogen Bonded

Polymorph (Ia) of eldoral [5-ethyl-5-(piperidin-1-yl)barbituric acid or 5-ethyl-5-(piperidin-1-yl)-1,3-diazinane-2,4,6-trione], C11H17N3O3, displays a hydrogen-bonded layer structure parallel to (100). The piperidine N atom and the barbiturate carbonyl group in the 2-position are utilized in N—H...N and N—H...O=C hydrogen bonds, respectively. The structure of polymorph (Ib) contains pseudosymmetry elements. The two independent molecules of (Ib) are connectedviaN—H...O=C(4/6-position) and N—H...N(piperidine) hydrogen bonds to give a chain structure in the [100] direction. The hydrogen-bonded layers, parallel to (010), formed in the salt diethylammonium 5-ethyl-5-(piperidin-1-yl)barbiturate [or diethylammonium 5-ethyl-2,4,6-trioxo-5-(piperidin-1-yl)-1,3-diazinan-1-ide], C4H12N+·C11H16N3O3−, (II), closely resemble the corresponding hydrogen-bonded structure in polymorph (Ia). Like many other 5,5-disubstituted derivatives of barbituric acid, polymorphs (Ia) and (Ib) contain theR22(8) N—H...O=C hydrogen-bond motif. However, the overall hydrogen-bonded chain and layer structures of (Ia) and (Ib) are unique because of the involvement of the hydrogen-bond acceptor function in the piperidine group.

Infrared spectroscopic characterization of hydrogen-bonded propylene oxide − ethanol and propylene oxide − 2-fluoroethanol complexes isolated in solid neon matrices

2013 ◽  
Vol 91 (12) ◽  
pp. 1292-1302 ◽  
Author(s):  
Osama Y. Ali ◽  
Elyse Jewer ◽  
Travis D. Fridgen
Keyword(s):  
Hydrogen Bond ◽  
Propylene Oxide ◽  
Spectroscopic Characterization ◽  
Hydrogen Bond Donor ◽  
Hydrogen Bond Acceptor ◽  
Reduced Frequency ◽  
Enthalpy Of Proton Transfer ◽  
The Difference ◽  
Bonded Complexes ◽  
Hydrogen Bonded

The infrared absorption spectra of hydrogen-bonded complexes of propylene oxide with either ethanol or 2-fluoroethanol have been recorded in neon matrices. Mixtures of propylene oxide and ethanol or propylene oxide and 2-fluoroethanol vapors were mixed with an excess of neon gas and deposited onto a KBr substrate at 4.2 K. The results indicate that hydrogen-bonded complexes were formed with propylene oxide as the hydrogen bond acceptor and either ethanol or 2-fluoroethanol as the hydrogen bond donors. The features assigned to the O−H stretch were red-shifted by 175 and 193 cm−1 for the ethanol- and 2-fluoroethanol-containing complexes, respectively. The difference in red shifts can be accounted for due to the greater acidity of 2-fluroethanol. Deuterium isotope experiments were conducted to help confirm the assignment of the O–H stretch for the complexes. As well, structures and infrared spectra were calculated using B3LYP/6-311++G(2d,2p) calculations and were used to compare with the experimental spectra. A “scaling equation” rather than a scaling factor was used and is shown to greatly increase the utility of the calculations when comparing with experimental spectra. An examination of the O–H stretching red shifts for many hydrogen-bound complexes reveals a relationship between the shift and the difference between the acidity of the hydrogen bond donor and the basicity of the hydrogen bond acceptor (the enthalpy of proton transfer). Both hydrogen-bonded complexes and proton-bound complexes appear to have a maximum in the reduced frequency value that corresponds to complexes where the hydrogen/proton are equally shared between the two bases.

Hirshfeld surface analysis of two new phosphorothioic triamide structures

2015 ◽  
Vol 71 (9) ◽  
pp. 824-833 ◽  
Author(s):  
Amir Hossein Alamdar ◽  
Mehrdad Pourayoubi ◽  
Anahid Saneei ◽  
Michal Dušek ◽  
Monika Kučeráková ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Solvent Molecule ◽  
Hirshfeld Surface ◽  
Two Dimensional ◽  
Asymmetric Unit ◽  
Hydrogen Bond Donor ◽  
Hydrogen Bond Acceptor ◽  
Double Hydrogen ◽  
Negligible Contribution

Hirshfeld surfaces and two-dimensional fingerprint plots are used to analyse the intermolecular interactions in two new phosphorothioic triamide structures, namelyN,N′,N′′-tris(3,4-dimethylphenyl)phosphorothioic triamide acetonitrile hemisolvate, P(S)[NHC6H3-3,4-(CH3)2]3·0.5CH3CN or C24H30N3PS·0.5CH3CN, (I), andN,N′,N′′-tris(4-methylphenyl)phosphorothioic triamide–3-methylpiperidinium chloride (1/1), P(S)[NHC6H4(4-CH3)]3·[3-CH3-C5H9NH2]+·Cl−or C21H24N3PS·C6H14N+·Cl−, (II). The asymmetric unit of (I) consists of two independent phosphorothioic triamide molecules and one acetonitrile solvent molecule, whereas for (II), the asymmetric unit is composed of three components (molecule, cation and anion). In the structure of (I), the different components are organized into a six-molecule aggregate through N—H...S and N—H...N hydrogen bonds. The components of (II) are aggregated into a two-dimensional array through N—H...S and N—H...Cl hydrogen bonds. Moreover, interesting features of packing arise in this structure due to the presence of a double hydrogen-bond acceptor (the S atom of the phosphorothioic triamide molecule) and of a double hydrogen-bond donor (the N—H unit of the cation). For both (I) and (II), the full fingerprint plot of each component is asymmetric as a consequence of the presence of three fragments. These analyses reveal that H...H interactions [67.7 and 64.3% for the two symmetry-independent phosphorothioic triamide molecules of (I), 30.7% for the acetonitrile solvent of (I), 63.8% in the phosphorothioic triamide molecule of (II) and 62.9% in the 3-methylpiperidinium cation of (II)] outnumber the other contacts for all the components in both structures, except for the chloride anion of (II), which only receives the Cl...H contact. The phosphorothioic triamide molecules of both structures include unsaturated C atoms, thus presenting C...H/H...C interactions: 17.6 and 21% for the two symmetry-independent phosphorothioic triamide molecules in (I), and 22.7% for the phosphorothioic triamide molecule of (II). Furthermore, the N—H...S hydrogen bonds in both (I) and (II), and the N—H...Cl hydrogen bonds in (II), are the most prominent interactions, appearing as large red spots on the Hirshfeld surface maps. The N...H/H...N contacts in structure (I) are considerable, whereas for (II), they give a negligible contribution to the total interactions in the system.

scholarly journals The influence of the solvent on organic reactivity. Part II. Hydroxylic solvent effects on the reaction rates of diazodiphenylmethane with 2-(2-substituted cyclohex-1-enyl)acetic and 2-(2-substituted

2004 ◽  
Vol 69 (8-9) ◽  
pp. 601-610 ◽  
Author(s):  
Jasmina Nikolic ◽  
Gordana Uscumlic ◽  
Vera Krstic
Keyword(s):  
Hydrogen Bond ◽  
Solvent Effects ◽  
Linear Regression Analysis ◽  
Solvent Polarity ◽  
Multiple Linear Regression Analysis ◽  
Reaction Rates ◽  
Hydrogen Bond Donor ◽  
Initial State ◽  
Hydrogen Bond Acceptor ◽  
Acetic Acids

The rate constants for the reaction of diazodiphenylmethane with 2-(2-substituted cyclohex-1-enyl)acetic acids and 2-(2-substituted phenyl)acetic acids, previously determined in seven hydroxylic solvents, were correlated using the total solvatochromic equation, of the form logk = logk0 + s?*+ a? + b?, the two-parameter model, logk=logk0 + s?*+ a? and a single parameter model logk = logk0 + b?, where ?*is a measure of the solvent polarity, ? represents the scale of solvent hydrogen bond acceptor basicities and ? represents the scale of solvent hydrogen bond donor acidities. The correlations of the kinetic data were carried out by means of multiple linear regression analysis and the solvent effects on the reaction rates were analyzed in terms of initial state and transition state contributions.

scholarly journals Synthesis and investigation of solvent effects on the ultraviolet absorption spectra of 1, 3-bis-substituted-5, 5-dimethylhydantoins

2003 ◽  
Vol 68 (10) ◽  
pp. 699-706 ◽  
Author(s):  
Gordana Uscumlic ◽  
Abdulbaseta Kshad ◽  
Dusan Mijin
Keyword(s):  
Hydrogen Bond ◽  
Absorption Spectra ◽  
Electronic Absorption Spectra ◽  
Alkyl Halide ◽  
Substituent Effects ◽  
Solvent Polarity ◽  
Hydrogen Bond Donor ◽  
Hydrogen Bond Acceptor ◽  
Isolation Techniques ◽  
Energy Relationships

A series of 1,3-bis-substituted-5,5-dimethylhydantoins was synthesized using the reaction of 5,5-dimethylhydantoin with the corresponding alkyl halide in the presence of trimethylamine as catalyst and sodium hydroxide, according to a modified literature procedure. The experimental investigation included modification of the synthetic procedure in terms of starting materials solvent, temperature, isolation techniques, as well as purification and identification of the products. The absorption spectra of the 1,3-bis-substituted-5,5-dimethylhydantoins were recorded in twelve solvents in the range 200?400 nm. The effects of the solvent polarity and hydrogen bonding on the absorption spectra were interpreted by means of linear solvation energy relationships using a general equation of the form ? = ?0 s?* + a? + b? and by two-parameter models presented by the equation ? = ?0 s?* + a?, where ?* is a measure of the solvent polarity/polarisability, ? is the scale of the solvent hydrogen bond donor acidities and ? is the scale of the solvent hydrogen bond acceptor basicities. The solvent and substituent effects on the electronic absorption spectra of the investigated hydantoins is discussed.

scholarly journals Crystal structure ofcis-tetraaquadichloridocobalt(II) sulfolane disolvate

2015 ◽  
Vol 71 (2) ◽  
pp. m16-m17 ◽  
Author(s):  
Mhamed Boudraa ◽  
Sofiane Bouacida ◽  
Hasna Bouchareb ◽  
Hocine Merazig ◽  
El Hossain Chtoun
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Crystal Packing ◽  
Rotation Axis ◽  
Water Molecules ◽  
Hydrogen Bond Donor ◽  
Linear Arrangement ◽  
Hydrogen Bond Acceptor ◽  
Chloride Ligand ◽  
Solvent Molecules

In the title compound, [CoCl2(H2O)4]·2C4H8SO2, the CoIIcation is located on the twofold rotation axis and is coordinated by four water molecules and two adjacent chloride ligands in a slightly distorted octahedral coordination environment. Thecisoidangles are in the range 83.27 (5)–99.66 (2)°. The threetransoidangles deviate significantly from the ideal linear angle. The crystal packing can be described as a linear arrangement of complex units alongcformed by bifurcated O—H...Cl hydrogen bonds between two water molecules from one complex unit towards one chloride ligand of the neighbouring complex. Two solvent molecules per complex are attached to this infinite chainviaO—H...O hydrogen bonds in which water molecules act as the hydrogen-bond donor and sulfolane O atoms as the hydrogen-bond acceptor sites.

Different acid–base behaviour of a pyrazole and an isoxazole with organic acids: crystal and molecular structures of the salt 3-(4-fluorophenyl)-1H-pyrazolium 2,4,6-trinitrophenolate and of the cocrystal 4-amino-N-(3,4-dimethyl-1,2-oxazol-5-yl)benzenesulfonamide–3,5-dinitrobenzoic acid (1/1)

2016 ◽  
Vol 72 (8) ◽  
pp. 612-618
Author(s):  
Marisiddaiah Girisha ◽  
Hemmige S. Yathirajan ◽  
Jerry P. Jasinski ◽  
Christopher Glidewell
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Molecular Structures ◽  
Hydrogen Bond Donor ◽  
Hydrogen Bond Acceptor ◽  
Form Complex ◽  
Carbocyclic Rings ◽  
Molecular Components ◽  
Related Compounds

Pyrazole and isoxazole rings differ only in the notional replacement of a potential hydrogen-bond-donor NH unit in pyrazole by a potential hydrogen-bond-acceptor O atom in isoxazole. It is thus of interest to compare the hydrogen-bonding characteristics of these rings. (4-Fluorophenyl)pyrazole undergoes protonation in the presence of 2,4,6-trinitrophenol to yield the salt 3-(4-fluorophenyl)-1H-pyrazolium 2,4,6-trinitrophenolate, C9H8FN2+·C6H2N3O7−, (I), whereas there is no proton transfer between 4-amino-N-(3,4-dimethyl-1,2-oxazol-5-yl)benzenesulfonamide and 3,5-dinitrobenzoic acid, whose reaction gives the 1:1 cocrystal, C11H13N3O3S·C7H4N2O6, (II). The bond lengths in salt (I) provide evidence for aromatic-type delocalization in the pyrazolium ring and for extensive delocalization of the negative charge into the ring of the trinitrophenolate anion. The O atoms of one of the nitro groups in the trinitrophenolate anion are disordered over two sets of atomic sites having occupancies of 0.571 (6) and 0.429 (6), but all of the other substituents on the carbocyclic rings are fully ordered. The ions in salt (I) are linked by an extensive series of N—H...O hydrogen bonds to form a three-dimensional framework structure, and in cocrystal (II), the molecular components are linked by a combination of O—H...N and N—H...O hydrogen bonds to form complex bilayers. Comparisons are made with some related compounds.

Poly[(μ3-benzene-1,4-dicarboxylato)di-μ-chlorido-(triethanolamine)dicadmium(II)]: a cadmium–halide coordination polymer with a hydrogen-bonded three-dimensional framework

2012 ◽  
Vol 68 (4) ◽  
pp. m109-m112 ◽  
Author(s):  
Xiyun He ◽  
Jianyi Lv ◽  
Guohai Xu
Keyword(s):  
Hydrogen Bond ◽  
Coordination Polymer ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
Hydrogen Bond Donor ◽  
One Dimensional ◽  
The One ◽  
Hydroxy Groups ◽  
Hydrogen Bonded

The structure of the title compound, [Cd2(C8H4O4)Cl2(C6H15NO3)]n, consists of one-dimensional chains in which each centrosymmetric tetranuclear Cd4Cl4O2cluster is terminated by two chelating triethanolamine (teaH3) ligands but linked to two adjacent clusters through four bridging benzene-1,4-dicarboxylate (bdc) ligands. The tetranuclear Cd4Cl4O2clusters are held togetherviabridging Cl and O atoms. Three directional hydrogen bonds from the multi-podal hydroxy groups of the teaH3ligand stabilize and extend the one-dimensional chains into a three-dimensional framework. All three hydroxy groups of the teaH3ligand form hydrogen bonds, illustrating the fact that the teaH3ligand can serve as an excellent hydrogen-bond donor.

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