Mixed crystals of 2-carbamoylguanidinium with hydrogen fluorophosphonate and hydrogen phosphite in the ratios 1:0, 0.76 (2):0.24 (2) and 0.115 (7):0.885 (7)

Author(s):  
Jan Fábry ◽  
Michaela Fridrichová ◽  
Michal Dušek ◽  
Karla Fejfarová ◽  
Radmila Krupková

The title compounds, 2-carbamoylguanidinium hydrogen fluorophosphonate, C2H7N4O+·HFO3P−, (I), 2-carbamoylguanidinium–hydrogen fluorophosphonate–hydrogen phosphite (1/0.76/0.24), C2H7N4O+·0.76HFO3P−·0.24H2O3P−, (II), and 2-carbamoylguanidinium–hydrogen fluorophosphonate–hydrogen phosphite (1/0.115/0.885), C2H7N4O+·0.115HFO3P−·0.885H2O3P−, (III), are isostructural with guanylurea hydrogen phosphite, C2H7N4O+·H2O3P−[Fridrichová, Němec, Císařová & Němec (2010).CrystEngComm,12, 2054–2056]. They constitute structures where the hydrogen phosphite anion has been fully or partially replaced by hydrogen fluorophosphonate. The title structures are the fourth example of isostructural compounds which differ by the presence of hydrogen fluorophosphonate and hydrogen phosphite or fluorophosphonate and phosphite anions. Moreover, the present study reports structures with these mixed anions for the first time. In the reported mixed salts, the P and O atoms of either anion overlap almost exactly, as can be judged by comparison of their equivalent isotropic displacement parameters, while the P—F and P—H directions are almost parallel. There are strong O—H...O hydrogen bonds between the anions, as well as strong N—H...O hydrogen bonds between the 2-carbamoylguanidinium cations in the title structures. Altogether they form a three-dimensional hydrogen-bond pattern. Interestingly, rare N—H...F interactions are also present in the title structures. Another exceptional feature concerns the P—O(H) distances, which are about as long as the P—F distance. The dependence of P—F distances on the longest P—O distances in FO3P2−or HFO3P−is presented. The greater content of hydrogen phosphite in the mixed crystals causes a larger deformation of the cations from planarity.

2004 ◽  
Vol 60 (2) ◽  
pp. 191-196 ◽  
Author(s):  
Maciej Kubicki

The case of prototropic annular tautomerism in an imidazole derivative has been found. The crystal structure contains a 50:50 mixture of two tautomers: 4-nitro-5-methoxyimidazole and 5-nitro-4-methoxyimidazole. The X-ray experiment actually shows the superposition of these compounds; it appears as if the structure is centrosymmetric and the N—H hydrogen atoms are disordered over two ring N atoms. Owing to the hydrogen-bond pattern, the values of their site occupation factors have to be exactly equal to 1/2. The molecules are connected into a three-dimensional network by means of N—H...N and C—H...O hydrogen bonds.


Author(s):  
Agnese Stikute ◽  
Karina Skestere ◽  
Inese Mierina ◽  
Anatoly Mishnev ◽  
Mara Jure

In the title compound, C16H20O4, a new starting compound for the synthesis of various heterocycles, the partially saturated six-membered ring adopts a sofa conformation. An intramolecular O—H...O hydrogen bond is observed in the guaiacol residue. In the crystal, molecules are assembled into a sheet structure parallel to the ab plane via O—H...O hydrogen bonds. The hydrogen-bond pattern is described by an R 4 4(28) graph-set motif. The sheets are further linked by C—H...O hydrogen bonds into a three-dimensional network.


2001 ◽  
Vol 58 (1) ◽  
pp. 94-108 ◽  
Author(s):  
Craig J. Kelly ◽  
Janet M. S. Skakle ◽  
James L. Wardell ◽  
Solange M. S. V. Wardell ◽  
John N. Low ◽  
...  

Molecules of N-(4′-iodophenylsulfonyl)-4-nitroaniline, 4-O2NC6H4NHSO2C6H4I-4′ (1), are linked by three-centre I...O2N interactions into chains and these chains are linked into a three-dimensional framework by C—H...O hydrogen bonds. In the isomeric N-(4′-nitrophenylsulfonyl)-4-iodoaniline, 4-IC6H4NHSO2C6H4NO2-4′ (2), the chains generated by the I...O2N interactions are again linked into a three-dimensional framework by C—H...O hydrogen bonds. Molecules of N,N-bis(3′-nitrophenylsulfonyl)-4-iodoaniline, 4-IC6H4N(SO2C6H4NO2-3′)2 (3), lie across twofold rotation axes in space group C2/c and they are linked into chains by paired I...O=S interactions: these chains are linked into sheets by a C—H...O hydrogen bond, and the sheets are linked into a three-dimensional framework by aromatic π...π stacking interactions. In N-(4′-iodophenylsulfonyl)-3-nitroaniline, 3-O2NC6H4NHSO2C6H4I-4′ (4), there are R^2_2(8) rings formed by hard N—H...O=S hydrogen bonds and R^2_2(24) rings formed by two-centre I...nitro interactions, which together generate a chain of fused rings: the combination of a C—H...O hydrogen bond and aromatic π...π stacking interactions links the chains into sheets. Molecules of N-(4′-iodophenylsulfonyl)-4-methyl-2-nitroaniline, 4-CH3-2-O2NC6H3NHSO2C6H4I-4′ (5), are linked by N—H...O=S and C—H...O(nitro) hydrogen bonds into a chain containing alternating R^2_2(8) and R^2_2(10) rings, but there are no I...O interactions of either type. There are two molecules in the asymmetric unit of N-(4′-iodophenylsulfonyl)-2-nitroaniline, 2-O2NC6H4NHSO2C6H4I-4′ (6), and the combination of an I...O=S interaction and a hard N—H...O(nitro) hydrogen bond links the two types of molecule to form a cyclic, centrosymmetric four-component aggregate. C—H...O hydrogen bonds link these four-molecule aggregates to form a molecular ladder. Comparisons are made with structures retrieved from the Cambridge Structural Database.


2012 ◽  
Vol 68 (6) ◽  
pp. o1614-o1615
Author(s):  
Tong Yu ◽  
Hai-Yan Tian ◽  
Xiao-Feng Yuan ◽  
Shu-Zhi Hu ◽  
Ren-Wang Jiang

The title compound, C24H30O5, is the didehydro product of the steroid hellebrigenin (systematic name: 3β,5,14-trihydroxy-19-oxo-5β-bufa-20,22-dienolide). It consists of three cyclohexane rings (A, B and C), a five-membered ring (D) and a six-membered lactone ring (E). The stereochemistry of the ring junctions are A/B cis, B/C trans and C/D cis. Cyclohexane rings A, B and C have normal chair conformations. The five-membered ring D with the C=C bond adopts an envelope conformation. Lactone ring E is essentially planar with a mean derivation of 0.006 (4) Å and is β-oriented at the C atom of ring D to which it is attached. There is an O—H...O hydrogen bond in the molecule involving the hydroxy groups. In the crystal, O—H...O hydrogen bonds link the molecules into chains propagating along [010]. The chains are linked by C—H...O contacts into a three-dimensional network.


2007 ◽  
Vol 63 (11) ◽  
pp. o4404-o4404 ◽  
Author(s):  
Shu-Ping Yang ◽  
Li-Jun Han ◽  
Da-Qi Wang ◽  
Hai-Tao Xia

In the title compound, C14H12BrNO2, the molecules are linked by one C—H...Br hydrogen bond, so forming a C(13) chain running parallel to the [010] direction, and these chains are linked by further C—H...π and C—H...Br hydrogen bonds, resulting in a three-dimensional network structure.


2013 ◽  
Vol 69 (12) ◽  
pp. o1781-o1781 ◽  
Author(s):  
M. Umadevi ◽  
V. Saravanan ◽  
R. Yamuna ◽  
A. K. Mohanakrishnan ◽  
G. Chakkaravarthi

In the title compound, C18H16ClNO2S, the indole ring system forms a dihedral angle of 75.07 (8)° with the phenyl ring. The molecular structure is stabilized by a weak intramolecular C—H...O hydrogen bond. In the crystal, molecules are linked by weak C—H...O hydrogen bonds, forming a chain along [10-1]. C—H...π interactions are also observed, leading to a three-dimensional network.


Author(s):  
Graham Smith ◽  
Urs D. Wermuth

In the structure of the brucinium salt of 4-aminophenylarsonic acid (p-arsanilic acid), systematically 2,3-dimethoxy-10-oxostrychnidinium 4-aminophenylarsonate tetrahydrate, (C23H27N2O4)[As(C6H7N)O2(OH)]·4H2O, the brucinium cations form the characteristic undulating and overlapping head-to-tail layered brucine substructures packed along [010]. The arsanilate anions and the water molecules of solvation are accommodated between the layers and are linked to them through a primary cation N—H...O(anion) hydrogen bond, as well as through water O—H...O hydrogen bonds to brucinium and arsanilate ions as well as bridging water O-atom acceptors, giving an overall three-dimensional network structure.


2015 ◽  
Vol 71 (12) ◽  
pp. o991-o992
Author(s):  
Kamel Ouari

In the title compound, C12H8BrN3O, the 4-bromophenol ring is coplanar with the planar imidazo[4,5-b]pyridine moiety (r.m.s deviation = 0.015 Å), making a dihedral angle of 1.8 (2)°. There is an intramolecular O—H...N hydrogen bond forming anS(6) ring motif. In the crystal, molecules are linkedviaN—H...N and O—H...Br hydrogen bonds, forming undulating sheets parallel to (10-2). The sheets are linked by π–π interactions [inter-centroid distance = 3.7680 (17) Å], involving inversion-related molecules, forming a three-dimensional structure.


2014 ◽  
Vol 70 (10) ◽  
pp. o1106-o1106
Author(s):  
Yong-Le Zhang ◽  
Chuang Zhang ◽  
Wei Guo ◽  
Jing Wang

In the title compound, C9H9N3OS, the plane of the benzene ring forms a dihedral angle of 33.40 (5)° with that of the triazole group. In the crystal, molecules are linked by O—H...N hydrogen bonds involving the phenol –OH group and one of the unsubstituted N atoms of the triazole ring, resulting in chains along [010]. These chains are further extended into a layer parallel to (001) by weak C—H...N hydrogen-bond interactions. Aromatic π–π stacking [centroid–centroid separation = 3.556 (1) Å] between the triazole rings links the layers into a three-dimensional network.


2006 ◽  
Vol 62 (4) ◽  
pp. 666-675 ◽  
Author(s):  
Christopher Glidewell ◽  
John N. Low ◽  
Janet M. S. Skakle ◽  
James L. Wardell

The structures of five of the possible six isomers of (E,E)-1,4-bis(nitrophenyl)-2,3-diaza-1,3-butadiene are reported, including two polymorphs of one of the isomers. (E,E)-1,4-Bis(2-nitrophenyl)-2,3-diaza-1,3-butadiene, C14H10N4O4 (I), crystallizes in two polymorphic forms (Ia) and (Ib) in which the molecules lie across centres of inversion in space groups P21/n and P21/c, respectively: the molecules in (Ia) and (Ib) are linked into chains by aromatic π...π stacking interactions and C—H...π(arene) hydrogen bonds, respectively. Molecules of (E,E)-1-(2-nitrophenyl)-4-(3-nitrophenyl)-2,3-diaza-1,3-butadiene (II) are linked into sheets by two independent C—H...O hydrogen bonds. The molecules of (E,E)-1,4-bis(3-nitrophenyl)-2,3-diaza-1,3-butadiene (III) lie across inversion centres in the space group P21/n, and a combination of a C—H...O hydrogen bond and a π...π stacking interaction links the molecules into sheets. A total of four independent C—H...O hydrogen bonds link the molecules of (E,E)-1-(3-nitrophenyl)-4-(4-nitrophenyl)-2,3-diaza-1,3-butadiene (IV) into sheets. In (E,E)-1,4-bis(4-nitrophenyl)-2,3-diaza-1,3-butadiene (V) the molecules, which lie across centres of inversion in the space group P21/n, are linked by just two independent C—H...O hydrogen bonds into a three-dimensional framework.


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