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1.
Bernard Omondi Demetrius C. Levendis Marcus Layh Manuel A. Fernandes 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(9):o470-o475
The structures of two distinct polymorphic forms of N‐(2,6‐difluorophenyl)formamide, C7H5F2NO, have been studied using single crystals obtained under different crystallizing conditions. The two forms crystallize in different space groups, viz. form (Ia) in the orthorhombic Pbca and form (Ib) in the monoclinic P21 space group. Each polymorph crystallizes with one complete molecule in the asymmetric unit and they have a similar molecular geometry, showing a trans conformation with the formamide group being out of the plane of the aromatic ring. The packing arrangements of the two polymorphs are quite different, with form (Ia) having molecules that are stacked in an alternating arrangement, linked into chains of N—H...O hydrogen bonds along the crystallographic a direction, while form (Ib) has its N—H...O hydrogen‐bonded molecules stacked in a linear fashion. A theoretical study of the two structures allows information to be gained regarding other contributing interactions, such as π–π and weak C—H...F, in their crystal structures. 相似文献
2.
Lithiation of N‐(2,6‐diisopropylphenyl)‐N′‐(2‐pyridylethyl)benzamidine ( 1 ) with LiN(SiMe3)2 in a solvent mixture of toluene and TMEDA yields hexameric lithium N‐(2,6‐diisopropylphenyl)‐N′‐(2‐pyridylethyl)benzamidinate ( 2 ), which can be purified by recrystallization from a solvent mixture of toluene and THF. The three‐coordinate lithium ions have T‐shaped coordination spheres. The negative charge is delocalized within the 1,3‐diazaallylic system, which adopts a (syn‐Z)‐arrangement. 相似文献
3.
Vijayakumar N. Sonar Sean Parkin Peter A. Crooks 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(3):o153-o154
In the title compound, C18H16N2O3, the indole ring is planar and the two adjacent carbonyl groups are mutually trans oriented with a torsion angle of 144.8 (3)°. The single C—C bond linking the two carbonyl functionalities is 1.539 (4) Å. Molecules are linked into a two‐dimensional network by intermolecular N—H⋯O hydrogen bonds. 相似文献
4.
Jia‐Xiang Yang Yu‐Peng Tian Qing‐Liang Liu Yong‐Shu Xie Hoong‐Kun Fun Suchada Chantrapromma Ibrahim Abdul Razak 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(1):m43-m44
In the title compound, [Fe(C5H5)(C16H12N3OS)], the 8‐aminoquinoline and acylthiourea moieties are almost planar. There are two perpendicular arrangements of the molecules in the crystal with slightly different conformations. The two cyclopentadienyl rings in each molecule are parallel and eclipsed. 相似文献
5.
Antonija Hergold‐Brundi Gordana Pavlovi Ana Dunja Mance Kreimir Jakop
i 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(11):e520-e521
The title compound, C15H14N2O3, is the first example of a structurally determined tertiary amine with both N‐5‐nitrofurfuryl and N‐prop‐2‐ynyl moieties. The molecule is not planar, i.e. the furan ring is inclined at an angle of 84.35 (4)° to the phenyl ring. The crystal structure is dominated by van der Waals forces. The terminal alkynyl group as the strongest C—H hydrogen‐bond donor is not involved in hydrogen‐bond formation. 相似文献
6.
Tuncay TuncÛ Musa Sar Rahmi Yagbasan Habibe Tezcan Ertan SÛahin 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(4):o192-o193
Molecules of the title compound (alternative name p‐methoxybenzaldehyde 2‐pyridylhydrazone), C13H13N3O, adopt an E configuration about the azomethine C=N double bond. Molecules are almost planar, the dihedral angle between the pyridine and methoxyphenyl rings being only 6.19 (12)°. Pairwise N—H⃛N hydrogen bonds [R(8) in graph‐set notation] link centrosymmetrically related molecules into discrete pairs. 相似文献
7.
Surprisingly Different Reaction Behavior of Alkali and Alkaline Earth Metal Bis(trimethylsilyl)amides toward Bulky N‐(2‐Pyridylethyl)‐N′‐(2,6‐diisopropylphenyl)pivalamidine 下载免费PDF全文
Diana Kalden Ansgar Oberheide Dr. Claas Loh Dr. Helmar Görls Dr. Sven Krieck Prof. Dr. Matthias Westerhausen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(31):10944-10959
N‐(2,6‐Diisopropylphenyl)‐N′‐(2‐pyridylethyl)pivalamidine (Dipp‐N=C(tBu)‐N(H)‐C2H4‐Py) ( 1 ), reacts with metalation reagents of lithium, magnesium, calcium, and strontium to give the corresponding pivalamidinates [(tmeda)Li{Dipp‐N=C(tBu)‐N‐C2H4‐Py}] ( 6 ), [Mg{Dipp‐N=C(tBu)‐N‐C2H4‐Py}2] ( 3 ), and heteroleptic [{(Me3Si)2N}Ae{Dipp‐N=C(tBu)‐N‐C2H4‐Py}], with Ae being Ca ( 2 a ) and Sr ( 2 b ). In contrast to this straightforward deprotonation of the amidine units, the reaction of 1 with the bis(trimethylsilyl)amides of sodium or potassium unexpectedly leads to a β‐metalation and an immediate deamidation reaction yielding [(thf)2Na{Dipp‐N=C(tBu)‐N(H)}] ( 4 a ) or [(thf)2K{Dipp‐N=C(tBu)‐N(H)}] ( 4 b ), respectively, as well as 2‐vinylpyridine in both cases. The lithium derivative shows a similar reaction behavior to the alkaline earth metal congeners, underlining the diagonal relationship in the periodic table. Protonation of 4 a or the metathesis reaction of 4 b with CaI2 in tetrahydrofuran yields N‐(2,6‐diisopropylphenyl)pivalamidine (Dipp‐N=C(tBu)‐NH2) ( 5 ), or [(thf)4Ca{Dipp‐N=C(tBu)‐N(H)}2] ( 7 ), respectively. The reaction of AN(SiMe3)2 (A=Na, K) with less bulky formamidine Dipp‐N=C(H)‐N(H)‐C2H4‐Py ( 8 ) leads to deprotonation of the amidine functionality, and [(thf)Na{Dipp‐N=C(H)‐N‐C2H4‐Py}]2 ( 9 a ) or [(thf)K{Dipp‐N=C(H)‐N‐C2H4‐Py}]2 ( 9 b ), respectively, are isolated as dinuclear complexes. From these experiments it is obvious, that β‐metalation/deamidation of N‐(2‐pyridylethyl)amidines requires bases with soft metal ions and also steric pressure. The isomeric forms of all compounds are verified by single‐crystal X‐ray structure analysis and are maintained in solution. 相似文献
8.
9.
Waseeq Ahmad Siddiqui Saeed Ahmad Hamid Latif Siddiqui Masood Parvez 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(7):o367-o371
The structures of 2‐[(2,3‐dimethylphenyl)carbamoyl]benzenesulfonamide, 2‐[(3,4‐dimethylphenyl)carbamoyl]benzenesulfonamide and 2‐[(2,6‐dimethylphenyl)carbamoyl]benzenesulfonamide, all C15H16N2O3S, are stabilized by extensive intra‐ and intermolecular hydrogen bonds. In all three structures, the sulfonamide and carbamoyl groups are involved in hydrogen bonding. In the 2,3‐dimethyl and 2,6‐dimethyl derivatives, dimeric units and chains of molecules are formed parallel to the c axis. In the 3,4‐dimethyl derivative, the hydrogen bonding creates tetrameric units, resulting in macrocyclic R44(22) rings that form sheets in the ab plane. The three analogues are closely related to the fenamate class of nonsteroidal anti‐inflammatory drugs. 相似文献
10.
Ashokkumar Subashini Kandasamy Ramamurthi Helen Stoeckli‐Evans 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(10):o408-o412
The 4‐chloro‐ [C14H11ClN2O2, (I)], 4‐bromo‐ [C14H10BrN2O2, (II)] and 4‐diethylamino‐ [C18H21N3O2, (III)] derivatives of benzylidene‐4‐hydroxybenzohydrazide, all crystallize in the same space group (P21/c), (I) and (II) also being isomorphous. In all three compounds, the conformation about the C=N bond is E. The molecules of (I) and (II) are relatively planar, with dihedral angles between the two benzene rings of 5.75 (12) and 9.81 (17)°, respectively. In (III), however, the same angle is 77.27 (9)°. In the crystal structures of (I) and (II), two‐dimensional slab‐like networks extending in the a and c directions are formed via N—H...O and O—H...O hydrogen bonds. The molecules stack head‐to‐tail viaπ–π interactions involving the aromatic rings [centroid–centroid distance = 3.7622 (14) Å in (I) and 3.8021 (19) Å in (II)]. In (III), undulating two‐dimensional networks extending in the b and c directions are formed via N—H...O and O—H...O hydrogen bonds. The molecules stack head‐to‐head viaπ–π interactions involving inversion‐related benzene rings [centroid–centroid distances = 3.6977 (12) and 3.8368 (11) Å]. 相似文献
11.
Under Lewis acid condition, N‐methyl‐3‐phenyl‐N‐(2‐(Z)‐phenylethenyl)‐cis‐oxiranecarboxamide undergoes elegant double cyclizations to give interesting products. 相似文献
12.
Abhijit Mitra Pamela J. Seaton Kraig A. Wheeler 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(9):o581-o582
The title new diquinaldine derivative, C27H24N4, forms molecular assemblies organized by intermolecular quinoline π–π stacking [3.356 (3) and 3.440 (3) Å] and both inter‐ and intramolecular N—H⋯N hydrogen bonds [3.039 (3)–3.104 (3) Å and 129 (2)–172 (2)°]. The combination of such interactions provides readily definable contacts that propagate along each crystallographic axis. 相似文献
13.
Triethylgermylation of sulfacetamide occurs on the sulfonamido nitrogen in competition with the 1,2 addition of the starting triethylgermyl dimethylamine on the carbonyl group. Thermal decomposition in the presence of dimethylamine yields N‐triethylgermylsulfanilamide. Stable 1:1 sulfacetamide–DBU and 1:1 sulfacetamide–Et3N complexes were isolated and fully characterized in the course of dehydrochlorination reactions. o‐Sulfonamidophenylamine yields N,N′‐bis‐triethylgermylated derivatives, whereas o‐(N,N‐dimethylsulfonamido)phenylamine leads to monogermylated compounds. The N‐dimethylaminodimesitylgermyl derivative is thermally stable. Dehydrohalogenation of the N‐dimesitylfluorogermyl compound leads to the thermally stable but water sensitive N‐[o‐(N′,N′‐dimethylsulfonamido)phenyl]‐N‐dimesitylgermaimine. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
14.
Julia Heilmann‐Brohl Matthias Wagner Hans‐Wolfram Lerner Michael Bolte 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(7):o364-o368
2‐{1‐[(4‐Chloroanilino)methylidene]ethyl}pyridinium chloride methanol solvate, C13H13ClN3+·Cl−·CH3OH, (I), crystallizes as discrete cations and anions, with one molecule of methanol as solvent in the asymmetric unit. The N—C—C—N torsion angle in the cation indicates a cis conformation. The cations are located parallel to the (02) plane and are connected through hydrogen bonds by a methanol solvent molecule and a chloride anion, forming zigzag chains in the direction of the b axis. The crystal structure of 2‐{1‐[(4‐fluoroanilino)methylidene]ethyl}pyridinium chloride, C13H13FN3+·Cl−, (II), contains just one anion and one cation in the asymmetric unit but no solvent. In contrast with (I), the N—C—C—N torsion angle in the cation corresponds with a trans conformation. The cations are located parallel to the (100) plane and are connected by hydrogen bonds to the chloride anions, forming zigzag chains in the direction of the b axis. In addition, the crystal packing is stabilized by weak π–π interactions between the pyridinium and benzene rings. The crystal of (II) is a nonmerohedral monoclinic twin which emulates an orthorhombic diffraction pattern. Twinning occurs via a twofold rotation about the c axis and the fractional contribution of the minor twin component refined to 0.324 (3). 2‐{1‐[(4‐Fluoroanilino)methylidene]ethyl}pyridinium chloride methanol disolvate, C13H13FN3+·Cl−·2CH3OH, (III), is a pseudopolymorph of (II). It crystallizes with two anions, two cations and four molecules of methanol in the asymmetric unit. Two symmetry‐equivalent cations are connected by hydrogen bonds to a chloride anion and a methanol solvent molecule, forming a centrosymmetric dimer. A further methanol molecule is hydrogen bonded to each chloride anion. These aggregates are connected by C—H...O contacts to form infinite chains. It is remarkable that the geometric structures of two compounds having two different formula units in their asymmetric units are essentially the same. 相似文献
15.
Tuncay TuncÛ Habibe Tezcan Musa Sar Orhan Büyükgüngr Rahmi Ya?basan 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(9):o528-o529
Molecules of the title compound (alternative name: p‐nitrobenzaldehyde phenylhydrazone), C13H11N3O2, adopt an E configuration about the azomethine C=N double bond. Molecules are approximately planar and the dihedral angle between the planes of the phenyl rings is 11.62 (9)°. Hydrogen bonding links molecules related by 42 screw axes to form helices with a pitch of 7.7186 (8) Å. 相似文献
16.
Mariya Edeleva Sylvain R. A. Marque Kuanish Kabytaev Yohann Guillaneuf Didier Gigmes Elena Bagryanskaya 《Journal of polymer science. Part A, Polymer chemistry》2013,51(6):1323-1336
Thermal decomposition of four tertiary N‐(2‐methylpropyl)‐N‐(1‐diethylphosphono‐2,2‐dimethylpropyl)‐N‐oxyl (SG1)‐based alkoxyamines (SG1‐C(Me)2‐C(O)‐OR, R = Me, tBu, Et, H) has been studied at different experimental conditions using 1H and 31P NMR spectroscopies. This experiment represents the initiating step of methyl methacrylate polymerization. It has been shown that H‐transfer reaction occurs during the decomposition of three alkoxyamines in highly degassed solution, whereas no products of H‐transfer are detected during decomposition of SG1‐MAMA alkoxyamine. The value of the rate constant of H‐transfer for alkoxyamines 1 (SG1‐C(Me)2‐C(O)‐OMe) and 2 ( SG1‐C(Me)2‐C(O)‐OtBu) has been estimated as 1.7 × 103 M?1s?1. The high influence of oxygen on decomposition mechanism is found. In particular, in poorly degassed solutions, nearly quantitative formation of oxidation product has been observed, whereas at residual pressure of 10?5 mbar, the main products originate from H‐atom transfer reaction. The acidity of the reaction medium affects the decomposition mechanism suppressing the H‐atom transfer. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
17.
Catherine Michaux Caroline Charlier Fabien Julmont Jean‐Michel Dogn Xavier De Leval Bernadette Norberg Bernard Pirotte Franois Durant 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(2):o88-o89
The title compound, C12H12N2O3S, is a strict pyridine analogue of nimesulide, a selective inhibitor of cyclooxygenase‐2. The structure is characterized by a pyridinium ring with a deprotonated sulfonamide group. An intermolecular charge‐assisted hydrogen bond between these two groups is observed within the crystal packing, linking the molecules into an infinite chain running along the b‐axis direction. 相似文献
18.
Valeriy E. Pashinnik Alexander I. Guzyr Alexei V. Borovikov Yuriy G. Shermolovich 《Heteroatom Chemistry》2005,16(5):352-356
2‐Benzothiazolyl‐N‐(arenesulfonyl)‐sulfinimidoyl fluorides were synthesized by the treatment of benzothiazolyl‐2‐sulfur trifluoride with sulfonamides. The reaction of 2‐benzothiazolyl‐N‐ (p‐toluenesulfonyl)‐sulfinimidoyl fluoride with tert‐ butylamine and morpholine gave 2‐benzothiazolyl‐ N‐(arenesulfonyl)‐sulfinimidoyl amides. The reaction of 2‐benzothiazolyl‐N‐(p‐toluenesulfonyl)‐sulfinimi‐ doyl fluoride or 2‐benzothiazolyl‐15N‐(p‐tosyl)sul‐ finimidoyl fluoride with S‐trimethylsilylbenzenethiol gave di(benzothiazolyl‐2) disulfide, fluorotrimethylsi‐ lane and N,N′‐bis(p‐toluenesulfonyl)‐N,N′‐bis(phenyl‐ thio)‐hydrazine or 15N,15N′‐bis(p‐toluenesulfonyl)‐15N, 15N′‐bis(phenylthio)‐hydrazine, respectively. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:352–356, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20102 相似文献
19.
Oscar F. Vazquez‐Vuelvas Julia V. Hernndez‐Madrigal Armando Pineda‐Contreras Simn Hernndez‐Ortega Reyna Reyes‐Martínez David Morales‐Morales 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(3):175-180
Two isomeric pyridine‐substituted norbornenedicarboximide derivatives, namely N‐(pyridin‐2‐yl)‐exo‐norbornene‐5,6‐dicarboximide, (I), and N‐(pyridin‐3‐yl)‐exo‐norbornene‐5,6‐dicarboximide, (II), both C14H12N2O4, have been crystallized and their structures unequivocally determined by single‐crystal X‐ray diffraction. The molecules consist of norbornene moieties fused to a dicarboximide ring substituted at the N atom by either pyridin‐2‐yl or pyridin‐3‐yl in an anti configuration with respect to the double bond, thus affording exo isomers. In both compounds, the asymmetric unit consists of two independent molecules (Z′ = 2). In compound (I), the pyridine rings of the two independent molecules adopt different conformations, i.e. syn and anti, with respect to the methylene bridge. The intermolecular contacts of (I) are dominated by C—H...O interactions. In contrast, in compound (II), the pyridine rings of both molecules have an anti conformation and the two independent molecules are linked by carbonyl–carbonyl interactions, as well as by C—H...O and C—H...N contacts. 相似文献
20.
The interaction between N‐(4‐ethoxyphenyl)‐N′‐(4‐antipyrinyl)thiourea (EPAT) and bovine serum albumin (BSA) was studied by fluorescence spectroscopy in combination with UV absorption spectroscopy. The intrinsic fluorescence of bovine serum albumin was quenched by EPAT through a static quenching procedure. The binding constants of EPAT with BSA were estimated according to the fluorescence quenching results at different temperatures. The thermodynamic parameters: enthalpy change (ΔH) and entropy change (ΔS) were calculated to be ?10.69 kJ/mol and 42.64 J·mol?1·K?1 according to thermodynamic equations, respectively, and indicating that the binding force was suggested to be mainly a hydrophobic force. The effect of common ions on the binding constant was also investigated. A new fluorescence spectroscopy assay of the proteins was presented in this paper. The determination results of the proteins in bovine serum by means of this method were very close to those obtained using Coomassie Brilliant Blue G‐250 colorimetry. 相似文献