The effect of hydrogen bonding on the bond lengths and angles in the carboxyl group

1979 ◽  
Vol 9 (2) ◽  
pp. 87-105 ◽  
Author(s):  
Mizuhiko Ichikawa
2007 ◽  
Vol 63 (11) ◽  
pp. o4450-o4451 ◽  
Author(s):  
Kaliyaperumal Thanigaimani ◽  
Packianathan Thomas Muthiah ◽  
Daniel E. Lynch

In the title cocrystal, C9H9N5·C6H8O2, the asymmetric unit contains one 2,4-diamino-6-phenyl-1,3,5-triazine molecule and a sorbic acid molecule. The triazine molecules are base-paired [with a graph set of R 2 2(8)] on either side via N—H...N hydrogen bonds, forming a supramolecular ribbon along the c axis. Each triazine molecule interacts with the carboxyl group of a sorbic acid molecule via N—H...O and O—H...N hydrogen bonds, generating R 2 2(8) motifs. The supramolecular ribbons are interlinked by N—H...O hydrogen bonds involving the 2-amino group of the triazine molecules and the carboxyl O atom of the sorbic acid molecule.


1967 ◽  
Vol 45 (14) ◽  
pp. 1699-1706 ◽  
Author(s):  
G. E. Dunn ◽  
Thomas L. Penner

The relative acidities of fifteen 4- and 5-substituted salicylic acids were determined in benzene solution by potentiometric titration. The potentials at half neutralization (h.n.p.) relative to that of salicylic acid were considered to measure the acidities of the substituted acids relative to the parent acid. These potentials, designated by Δhnp, gave a significantly better correlation with Hammett's sigma constants in an equation of the form proposed by Jaffe, Δhnp = ρ1σ1 + ρ2σ2, than in a simple Hammett equation, Δhnp = ρ1σ1. In these equations the subscripts 1 and 2 refer to the position of a substituent relative to the carboxyl group and to the phenolic group respectively. The value of ρ2/ρ1 was found to be 0.4, indicating that the electronic effect of a substituent on the acid strength via the phenolic hydrogen-bonded path is almost half as large as the direct effect through the carboxyl group. These results, together with the fact that in aqueous solution there is very little if any transmission via the phenolic group, are discussed in terms of intramolecular hydrogen bonding of salicylic acids in benzene and in water.


1993 ◽  
Vol 51 (1-2) ◽  
pp. 288
Author(s):  
C.K. Chang ◽  
Y. Liang ◽  
G. Avilés ◽  
E. Schmidt ◽  
S.-M. Peng

2007 ◽  
Vol 63 (3) ◽  
pp. o1173-o1175
Author(s):  
Stephanie M. Witko ◽  
Mark Davison ◽  
Hugh W. Thompson ◽  
Roger A. Lalancette

In the title crystal structure, C9H14O3·H2O, the water molecule accepts a hydrogen bond from the carboxyl group [O...O = 2.6004 (13) Å and O—H...O = 163°], while donating hydrogen bonds to the ketone [O...O = 2.8193 (14) Å and O—H...O = 178 (2)°] and the acid carbonyl groups [O...O = 2.8010 (14) Å and O—H...O = 174 (2)°]. This creates a network of hydrogen bonds confined within a continuous flat ribbon two molecules in width and extending in the [101] direction.


2017 ◽  
Vol 73 (7) ◽  
pp. 1021-1025
Author(s):  
Francois Eya'ane Meva ◽  
Timothy John Prior ◽  
David John Evans ◽  
Emmanuel Roland Mang

The crystal structures ofN′-aminopyridine-2-carboximidamide (C6H8N4),1, andN′-{[1-(pyridin-2-yl)ethylidene]amino}pyridine-2-carboximidamide (C13H13N5),2, are described. The non-H atoms in compound1are nearly planar (r.m.s. deviation from planarity = 0.0108 Å), while2is twisted about the central N—N bond by 17.8 (2)°. Both molecules are linked by intermolecular N—H...N hydrogen-bonding interactions;1forms a two-dimensional hydrogen-bonding network and for2the network is a one-dimensional chain. The bond lengths of these molecules are similar to those in other literature reports of azine and diimine systems.


2006 ◽  
Vol 62 (7) ◽  
pp. o2976-o2978 ◽  
Author(s):  
Kaliyaperumal Thanigaimani ◽  
Packianathan Thomas Muthiah ◽  
Daniel E. Lynch

In the title cocrystal, C6H9N3O2·C7H7NO2, the 2-amino-4,6-dimethoxypyrimidine molecule interacts with the carboxyl group of the 4-aminobenzoic acid molecule through N—H...O and O—H...N hydrogen bonds, forming a cyclic hydrogen-bonded motif [R 2 2(8)]. This motif further self-organizes through N—H...O hydrogen bonds to generate an array of six hydrogen bonds with the rings having the graph-set notation R 2 3(6), R 2 2(8), R 4 2(8), R 2 2(8) and R 2 3(6). The 4-aminobenzoic acid molecules self-assemble via N—H...O hydrogen bonds to form a supramolecular chain along the c axis.


1998 ◽  
Vol 54 (6) ◽  
pp. 1194-1198 ◽  
Author(s):  
A. Guy Orpen

The origins, scope and utility of compilations of metal–ligand and intraligand bond lengths based on the Cambridge Structural Database are discussed. The limitations on the apparent uncertainty of metal–ligand bond lengths derived from crystallographic data and recent evidence of metal-assisted hydrogen bonding involving ligands are reviewed in the light of the transferability of bond-length values from one crystal structure determination.


1986 ◽  
Vol 41 (12) ◽  
pp. 1485-1489 ◽  
Author(s):  
Christian Robl ◽  
Armin Weiss

Abstract BaC4O4-3H2O was prepared by crystallization in aqueous silica gel. The crystal structure is a complicated three-dimensional framework. Ba2+ has CN 8+1. It is surrounded by 5 water molecules and 4 Osquarate atoms (Ba-O distances from 271.1 to 324.2 pm). The squarate dianion is almost planar and shows C -C and C-O bond lengths indicating the existence of resonance stabilization, although one Osquarate atom is not connected to Ba2+ at all. Short water-Osquarate distances hint to strong hydrogen bonding which obviously plays an important part in this structure.


2015 ◽  
Vol 71 (1) ◽  
pp. 26-31 ◽  
Author(s):  
Jan W. Bats ◽  
Kuangbiao Ma ◽  
Hans-Wolfram Lerner

Crystal structures are reported for four (2,2′-bipyridyl)(ferrocenyl)boronium derivatives, namely (2,2′-bipyridyl)(ethenyl)(ferrocenyl)boronium hexafluoridophosphate, [Fe(C5H5)(C17H15BN2)]PF6, (Ib), (2,2′-bipyridyl)(tert-butylamino)(ferrocenyl)boronium bromide, [Fe(C5H5)(C19H22BN3)]Br, (IIa), (2,2′-bipyridyl)(ferrocenyl)(4-methoxyphenylamino)boronium hexafluoridophosphate acetonitrile hemisolvate, [Fe(C5H5)(C22H20BN3O)]PF6·0.5CH3CN, (IIIb), and 1,1′-bis[(2,2′-bipyridyl)(cyanomethyl)boronium]ferrocene bis(hexafluoridophosphate), [Fe(C17H14BN3)2](PF6)2, (IVb). The asymmetric unit of (IIIb) contains two independent cations with very similar conformations. The B atom has a distorted tetrahedral coordination in all four structures. The cyclopentadienyl rings of (Ib), (IIa) and (IIIb) are approximately eclipsed, while a bisecting conformation is found for (IVb). The N—H groups of (IIa) and (IIIb) are shielded by the ferrocenyl andtert-butyl or phenyl groups and are therefore not involved in hydrogen bonding. The B—N(amine) bond lengths are shortened by delocalization of π-electrons. In the cations with an amine substituent at boron, the B—N(bipyridyl) bonds are 0.035 (3) Å longer than in the cations with a methylene C atom bonded to boron. A similar lengthening of the B—N(bipyridyl) bonds is found in a survey of related cations with an oxy group attached to the B atom.


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