scholarly journals Synthesis and crystal structure of peptide dimethyl biphenyl hybrid C52H60N6O10·0.25H2O

2020 ◽  
Vol 76 (10) ◽  
pp. 1675-1678
Author(s):  
Xuan Tu Nguyen ◽  
Thuy Quynh Le ◽  
Tra My Bui Thi ◽  
Dinh Hung Mac ◽  
Thai Thanh Thu Bui

The synthesis and crystal structure of peptide 6,6′-dimethyl biphenyl hybrid are described. The title compound was synthesized by reaction between 6,6′-dimethyl-[1,1′-biphenyl]-2,2′-dicarbonyl dichloride in CH2Cl2, amine HN–proline–phenylalanine–alanine–COOMe and Et3N at 273 K under N2 atmosphere and characterized by single-crystal X-ray diffraction. The asymmetric unit contains one peptide molecule and a quarter of a water molecule. A disorder of a methyl and methoxycarbonyl group of one alanine residue is observed with occupancy ratio 0.502 (6):0.498 (6). The structure is consolidated by intra- and intermolecular hydrogen bonds.

2013 ◽  
Vol 634-638 ◽  
pp. 451-455
Author(s):  
Yan Yang ◽  
Liu Ting Yan ◽  
Rong Huan Qin ◽  
Wen Gui Duan

The lead(II) Complex constructed with 5-hydroxyisophthalic acid, [Pb3(5-hipa)2]n•4H2O(1), (5-hipa = 5-hydro- xyisophthalic acid) has been synthesized by hydrothermal methods and structurally characterized by elemental analysis, IR and X-ray single crystal diffraction. In trinuclear symmetrical complex 1, Pb1 is four-coordinated, Pb2 and Pb3 are three-coordinated by 5-nitroisophthalic acid groups, respectively, which is further connected through intermolecular hydrogen bonds resulting in a three-dimensional (3D) network.


Author(s):  
Dohyun Moon ◽  
Jong-Ha Choi

The crystal structure of the title complex, cis-[Cr(NCS)2(cyclam)]Br (cyclam = 1,4,8,11-tetraazacyclotetradecane, C10H24N4), has been determined from synchrotron X-ray data. The asymmetric unit contains one [Cr(NCS)2(cyclam)]+ cation and one bromide anion. The CrIII ion of the complex cation is coordinated by the four N atoms of the cyclam ligand and by two N-coordinating NCS groups in a cis arrangement, displaying a distorted octahedral coordination sphere. The Cr—N(cyclam) bond lengths are in the range 2.075 (3) to 2.081 (3) Å while the average Cr—N(NCS) bond length is 1.996 (16) Å. The macrocyclic cyclam moiety adopts the most stable cis-V conformation. The crystal structure is stabilized by intermolecular hydrogen bonds involving the cyclam N—H groups as donor groups, and the bromide anion and the S atom of one of the NCS ligands as acceptor groups.


1996 ◽  
Vol 51 (8) ◽  
pp. 1084-1098 ◽  
Author(s):  
Rolf W. Saalfrank ◽  
Bernd Hörner ◽  
Stephan Reck ◽  
Jochen Nachtrab ◽  
Eva-Maria Peters ◽  
...  

Reaction of malondiamides 1 with oxalyl chloride (2) leads to the formation of 2,3-dioxo-2,3- dihydrofuran hydrochlorides 3 and 2,3-dioxo-2,3-dihydro-furanes 4, respectively. The structure of 3a was established by X-ray diffraction. The β-oxo-dibenzylamides 5 react with 2 regiospecifically to give the 2,3-dioxo-2,3-dihydrofuranes 6. Addition of water in 1,4-position to 6a yields hydroxy-enol 7, which forms bimolecular aggregates via intermolecular hydrogen bonds as shown by X-ray analysis. Intramolecular C,N-bisacylation of β-oxoamides 8 and malondiamides 11 with 2 leads to the pyrrol-2,5-diones 9 and 12. Reaction of the enols 9 and 12 with thionyl chloride leads to 3-chloro-pyrrol-2,5-diones 13. 3-Amino-pyrrol-2,5-diones 15 are obtained from 13 and amines 14, while 1, ω-diamines 16 yield the bispyrrol systems 17. X-ray diffraction analysis of 17g reveals a supramolecular ribbon based on intermolecular hydrogen bonds between two different conformeres of 17g and in addition establishes unequivocally the imid-structures of 9 and 12. Intermolecular cyclisation of 13 with amino-tetrazol 18 gives the azido-pyrrolo-pyrimidine-diones 20, which reacts with triphenylphosphane to give phosphinimines 22. The structure of 22a was established by X-ray diffraction.


Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1407
Author(s):  
Toshifumi Yui ◽  
Takuya Uto ◽  
Kozo Ogawa

We determined the molecular and packing structure of a chitosan–ZnCl2 complex by X-ray diffraction and linked-atom least-squares. Eight D-glucosamine residues—composed of four chitosan chains with two-fold helical symmetry, and four ZnCl2 molecules—were packed in a rectangular unit cell with dimensions a = 1.1677 nm, b = 1.7991 nm, and c = 1.0307 nm (where c is the fiber axis). We performed exhaustive structure searches by examining all of the possible chain packing modes. We also comprehensively searched the positions and spatial orientations of the ZnCl2 molecules. Chitosan chains of antiparallel polarity formed zigzag-shaped chain sheets, where N2···O6, N2···N2, and O6···O6 intermolecular hydrogen bonds connected the neighboring chains. We further refined the packing positions of the ZnCl2 molecules by theoretical calculations of the crystal models, which suggested a possible coordination scheme of Zn(II) with an O6 atom.


Author(s):  
Dohyun Moon ◽  
Jong-Ha Choi

The crystal structure of the hydrated title salt, C22H48N4 4+·4Cl−·4H2O (C22H48N4 = H4 L = 3,14-diethyl-2,6,13,17-tetraazoniatricyclo[16.4.0.07,12]docosane), has been determined using synchrotron radiation at 220 K. The structure determination reveals that protonation has occurred at all four amine N atoms. The asymmetric unit comprises one half of the macrocyclic cation (completed by crystallographic inversion symmetry), two chloride anions and two water molecules. The macrocyclic ring of the tetracation adopts an exodentate (3,4,3,4)-D conformation. The crystal structure is stabilized by intermolecular hydrogen bonds involving the macrocycle N—H groups and water O—H groups as donors, and the O atoms of the water molecules and chloride anions as acceptors, giving rise to a three-dimensional network.


2011 ◽  
Vol 418-420 ◽  
pp. 59-62
Author(s):  
Yan Yang ◽  
Liu Ting Yan ◽  
Xiao Li ◽  
Rong Huan Qin ◽  
Wen Gui Duan

The Cobalt (Ⅱ) Complex constructed with 5-nitroisophthalic acid and 2,2’-bibenzimidazole, [Co(H2bibim)2( 5-nipa)] (1), (H2bibim =2,2’-bibenzimidazole, 5-nipa=5-nitroisophthalic acid) have been synthesized by hydrothermal methods and structurally characterized by elemental analysis, IR and X-ray single crystal diffraction. Complex 1 has six coordinated by two H2bibim ligands and one 5-nitroisophthalic acid groups that is further connected though intermolecular hydrogen bonds and resulting in a three-dimensional (3D) network.


2012 ◽  
Vol 554-556 ◽  
pp. 852-855
Author(s):  
Hai Xing Liu ◽  
Jing Zhong Xiao ◽  
Lan Xu ◽  
Vitor Hugo Nunes Rodrigues ◽  
Manuela Ramos Marques da Silva ◽  
...  

A new vanadium complex [ V(C12H8N2) ·O2·(H2O)]·NO3·H2O h as been synthesized from a simple reaction and the crystal structure has been determined by means of single-crystal X-ray diffraction. Monoclinic, P2(1)/c. a = 9.5137(2) Å b = 19.3181(4) Å c = 7.51800(10) Å α=γ=90 β= 93.6830. V= 1378.85(4) Å3. Z=2. Rgt(F) = 0.0255, wRref(F2) = 0.0809. T= 273(2) K. The compound consisted of a [ V(C12H8N2) ·O2·(H2O)]+ cation, one NO3-anion and one water molecular. Molecule structure is stabilized by OHN , OHO intramolecular and intermolecular hydrogen bonds.


1992 ◽  
Vol 47 (4) ◽  
pp. 460-464 ◽  
Author(s):  
Klaus Brodersen ◽  
Jürgen Hofmann

The structure of bis(m-aminobenzonitrile)dimercury(I) dinitrate, [Hg2(m -NH2C6H4CN)2](NO3)2 has been determined by single crystal X-ray diffraction techniques and refined to an Rw-value of 0.022. The crystals are triclinic, space group P1 with a = 5.4878(1) Å, b = 8.4085(1) Å, c = 9.6062(1) Å, α = 92.599(3)°, β = 94.763(3)°, γ = 89.614(3)° and Z = 1.The Hg22+-ion [Hg-Hg 2.524(1) Å] is approximately axially coordinated to amino nitrogen atoms [Hg - N 2.209(4) Å, Hg - Hg - N 169.5(3)°]. Additional amino hydrogen bonds to oxygen are building chains along the b-axis containing units of L - Hg - Hg - L groups.


2011 ◽  
Vol 279 ◽  
pp. 174-178
Author(s):  
Sheng Liang Ni ◽  
Yue Meng ◽  
Pei Song Tang

Reactions of a freshly prepared Zn(OH)2-2x(CO3)x×yH2O precipitate, formic acid with 2,9’-dimethyl-1,10’-phenanthroline in CH3OH/H2O afforded [Zn(C14H12N2)(HCO2)2]·2H2O. The title compound was structurally characterized by X-ray diffraction methods. It consists of complex molecules [Zn(C14H12N2)(HCO2)2] in which Zn atoms are hexa-coordinated by two N atoms of one phenanthroline ligand and four O atoms of two bidentate formate groups. In the crystal, molecules are connected by O–H···O hydrogen bonds forming layers parallel to (010), and the resulting layers are further linked 3D framework along [100] by π-π packing interactions.


2006 ◽  
Vol 61 (10) ◽  
pp. 1198-1204 ◽  
Author(s):  
Ibrahim Kani ◽  
Orhan Büyükgüngör ◽  
Filiz Şişman

The hexacoordinated mononuclear Co(III) complex 1, [Co(HL)(phen)2(H2O)]L·H2O, with the mixed ligands (H2L = HO2C(CF2)8CO2H and 1,10-phenantroline) has been synthesized and characterized by elemental analysis, IR and UV/vis spectroscopy, magnetic susceptibility, TG analysis and X-ray diffraction techniques. The Co(III) atom is coordinated asymmetrically by two bidentate 1,10 phenanthroline ligands, one hydrogencarboxylate ligand, (O2C(CF2)8CO2H)−, and one water molecule. In the crystal structure, there are also dicarboxylate anions and one water molecule attached through hydrogen bonds. Intermolecular π-π interactions between the adjacent phenanthroline ligands also support the packing of the components.


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