Self-Assembly of Cationic, Tetranuclear, Pt(II) and Pd(II) Macrocyclic Squares. x-ray Crystal Structure of [Pt2+(dppp)(4,4'-bipyridyl).cntdot.2-OSO2CF3]4

1995 ◽  
Vol 117 (23) ◽  
pp. 6273-6283 ◽  
Author(s):  
Peter J. Stang ◽  
Danh H. Cao ◽  
Shinichi Saito ◽  
Atta M. Arif
Keyword(s):  
Crystal Structure ◽  
Self Assembly ◽  
X Ray

Synthesis of palladium and platinum donor complexes and study of their participation in self-assembly reactions. X-ray crystal structure of [Pt(C6H4CCC5H4N)2(dppp)] (dppp=1,3-bis(diphenylphosphino)propane)

2005 ◽  
Vol 690 (6) ◽  
pp. 1612-1619 ◽  
Author(s):  
Montserrat Ferrer ◽  
Laura Rodrı́guez ◽  
Oriol Rossell ◽  
Xavier Solans
Keyword(s):  
Crystal Structure ◽  
Self Assembly ◽  
X Ray

Self-assembling triazolophanes: from croissants through donuts to spherical vesicles

2015 ◽  
Vol 51 (32) ◽  
pp. 6905-6908 ◽  
Author(s):  
V. Haridas ◽  
Appa Rao Sapala ◽  
Jerry P. Jasinski
Keyword(s):  
Crystal Structure ◽  
Self Assembly ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
X Ray ◽  
Self Assembling ◽  
Assembly Mechanism ◽  
Spherical Vesicles

A detailed ultramicroscopic analysis of three novel triazolophanes demonstrated a hierarchical self-assembly mechanism. These macrocycles self-assemble in a concentration dependent manner to hemi-toroids, toroids and finally to vesicles. The finding was supported by ultramicroscopy and X-ray crystal structure studies.

scholarly journals Heat induces end to end repetitive association in P. furiosus l-asparaginase which enables its thermophilic property

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Pankaj Sharma ◽  
Rachana Tomar ◽  
Shivpratap Singh Yadav ◽  
Maulik D. Badmalia ◽  
Samir Kumar Nath ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Self Assembly ◽  
Elevated Temperatures ◽  
Contact Point ◽  
Saxs Data ◽  
X Ray ◽  
X Ray Scattering ◽  
Crystallographic Structures ◽  
End To End ◽  
Enhanced Stability

AbstractIt remains undeciphered how thermophilic enzymes display enhanced stability at elevated temperatures. Taking l-asparaginase from P. furiosus (PfA) as an example, we combined scattering shapes deduced from small-angle X-ray scattering (SAXS) data at increased temperatures with symmetry mates from crystallographic structures to find that heating caused end-to-end association. The small contact point of self-binding appeared to be enabled by a terminal short β-strand in N-terminal domain, Leu179-Val-Val-Asn182 (LVVN). Interestingly, deletion of this strand led to a defunct enzyme, whereas suplementation of the peptide LVVN to the defunct enzyme restored structural frameworkwith mesophile-type functionality. Crystal structure of the peptide-bound defunct enzyme showed that one peptide ispresent in the same coordinates as in original enzyme, explaining gain-of lost function. A second peptide was seen bound to the protein at a different location suggesting its possible role in substrate-free molecular-association. Overall, we show that the heating induced self-assembly of native shapes of PfA led to an apparent super-stable assembly.

scholarly journals Synthesis, X-ray Crystal Structure and Antimicrobial Activity of Unexpected Trinuclear Cu(II) Complex from s-Triazine-Based Di-Compartmental Ligand via Self-Assembly

Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 661
Author(s):  
Saied M. Soliman ◽  
Jamal Lasri ◽  
Matti Haukka ◽  
Essam N. Sholkamy ◽  
Hessa H. Al-Rasheed ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Antimicrobial Activity ◽  
Self Assembly ◽  
Wide Spectrum ◽  
Free Ligand ◽  
Salmonella Typhi ◽  
Positive Control ◽  
Distorted Octahedral Geometry ◽  
X Ray ◽  
Π Stacking

The synthesis and X-ray crystal structure of the trinuclear [Cu3(HL)(Cl)2(NO3)(H2O)5](NO3)2 complex of the s-triazine-based di-compartmental ligand, 2-methoxy-4,6-bis(2-(pyridin-2-ylmsethylene)hydrazinyl)-1,3,5-triazine (H2L), are presented. The Cu1 and Cu2 are penta-coordinated with CuN3ClO coordination environment, distorted square pyramidal coordination geometry while Cu3 is hexa-coordinated with CuN2O4 coordination sphere, and distorted octahedral geometry. The complex crystallized in the primitive P-1 triclinic crystal system with two molecular units per unit cell. Its packing is dominated by the O–H (35.5%) and Cl–H (8.8%) hydrogen bonding interactions as well as the π–π stacking (2.3%) and anion–π-stacking interactions (3.7%). The different coordination interactions were analyzed using atoms in molecules (AIM) theory, and the number of charge transferences from the ligand group to Cu(II) were determined using natural bond orbital calculations. The effect of the free ligand and its Cu(II) complex on the tested pathogenic microbes (Staphylococcus aureus, S. epidermidis, Enterococcus faecalis, Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa) and one fungal isolate (Candida albicans) is presented. Both have wide spectrum antimicrobial activity against the selected microorganism. It is observed that the free ligand at 180 µg/mL was more effective than its Cu(II) complex and showed close results compared to the positive control gentamicin. At higher concentrations (1 mg/mL), the Cu(II) complex was found to be more active against S. epidermidis, E. coli and C. albicans than the lower concentration. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values are also lower for the Cu(II) complex than the free ligand.

Synthesis and crystal structure of an M 4 L 6 tetrahedral cage with outward-facing pockets from a substituted pyrazolyl–pyridine ligand

2018 ◽  
Vol 74 (8) ◽  
pp. 961-966
Author(s):  
Nawal K. Al Rasbi ◽  
Michael D. Ward
Keyword(s):  
Crystal Structure ◽  
Self Assembly ◽  
The Self ◽  
Pyridyl Ring ◽  
Current Interest ◽  
Pyridine Ligand ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Polydentate Ligands ◽  
Tetrahedral Complexes

The self-assembly of metal–polydentate ligands to give supramolecular tetrahedral complexes is of considerable current interest. A new ligand, 4-benzyl-2-[1-(2-{[3-(4-benzylpyridin-2-yl)-1H-pyrazol-1-yl]methyl}benzyl)-1H-pyrazol-3-yl]pyridine (L), with chelating pyrazolyl–pyridine units substituted on the 4-position of the pyridyl ring with benzyl units, has been synthesized and fully characterized. The self-assembly of L with cobalt(II) gave rise to a tetrahedral cage (hexakis{μ-4-benzyl-2-[1-(2-{[3-(4-benzylpyridin-2-yl)-1H-pyrazol-1-yl]methyl}benzyl)-1H-pyrazol-3-yl]pyridine}perchloratotetracobalt(II) octakis(perchlorate) acetonitrile undecasolvate, [Co4(ClO4)(C38H32N6)6](ClO4)7·11CH3CN) with approximate T symmetry. The X-ray crystal structure of the cage, i.e. [Co4 L 6\subsetClO4](ClO4)7, shows that the substituted benzyl groups are oriented away from the centres of their respective ligands towards the CoII vertices, making small outward-facing pockets from three benzyl rings at the corners of the tetrahedron.

Cation supported self-assembly of coordination polymers, [(H2en)(ntpMCl2)]n (M=ZnII, CdII, HgII) involving the tripodal acid, ntp: X-ray crystal structure and DNA binding studies on zinc helicate

Polyhedron ◽  
2006 ◽  
Vol 25 (15) ◽  
pp. 2929-2934 ◽  
Author(s):  
Mohammad Shakir ◽  
Shama Parveen ◽  
Poonam Chingsubam ◽  
Katsuyuki Aoki ◽  
Shahper N Khan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Dna Binding ◽  
Coordination Polymers ◽  
Self Assembly ◽  
Binding Studies ◽  
X Ray ◽  
Dna Binding Studies

Self-assembly and X-ray crystal structure of a six-component metallosupramolecular box

1998 ◽  
Vol 1 (4) ◽  
pp. 147-149 ◽  
Author(s):  
Brendan J. O'Keefe ◽  
Peter J. Steel
Keyword(s):  
Crystal Structure ◽  
Self Assembly ◽  
X Ray

scholarly journals Fabrication, Characterization of SiO2 Nanospheres and SiO2 Opal Photonic Crystals

2021 ◽  
Vol 37 (1) ◽  
Author(s):  
Nguyen Duy Thien ◽  
Nguyen Ngoc Tu ◽  
Nguyen Quang Hoa ◽  
Sai Cong Doanh ◽  
Le Van Vu
Keyword(s):  
Crystal Structure ◽  
Photonic Crystals ◽  
Self Assembly ◽  
Diffuse Reflection ◽  
X Ray Diffraction ◽  
Stöber Method ◽  
X Ray ◽  
Structure And Morphology ◽  
Assembly Method

In this report, we presented the usage of Stober method to fabricate SiO2 nanospheres and self-assembly method to make SiO2 opal photonic crystals based on the fabricated SiO2 nanospheres. An averaged size of SiO2 nanospheres was controlled by varying concentrations of NH4OH and TEOS. Crystal structure and morphology of particles was investigated by using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Experimental results showed that SiO2 nanospheres possess amorphous crystal structure with sizes ranged from 150 to 300 nm. The diffuse reflection spectra show the reflection peaks of the SiO2 opal photonic crystals from 410 nm to 520 nm.  

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