The complex between ribonuclease T1 and 3'GMP suggests geometry of enzymic reaction path. An X-ray study

1993 ◽  
Vol 218 (3) ◽  
pp. 1005-1012 ◽  
Author(s):  
Andrea HEYDENREICH ◽  
Gertraud KOELLNER ◽  
Hui-Woog CHOE ◽  
Frank CORDES ◽  
Caroline KISKER ◽  
...  
Keyword(s):  
Reaction Path ◽  
Ribonuclease T1 ◽  
X Ray ◽  
Enzymic Reaction

Conformation of 2′GMP Bound to a Mutant Ribonuclease T1 (Y45W) Determined by X-Ray Diffraction and NMR Methods1

1991 ◽  
Vol 110 (5) ◽  
pp. 677-680 ◽  
Author(s):  
Takeshi Itoh ◽  
Ken-ichi Tomita ◽  
Toshio Hakoshima ◽  
Hidekazu Hiroaki ◽  
Sei-ichi Uesugi ◽  
...  
Keyword(s):  
X Ray Diffraction ◽  
Ribonuclease T1 ◽  
X Ray

Scholl Reaction of an ortho-Phenylene-bridged Cyclic Pyrrole-Thiophene Hybrid Hexamer

Synthesis ◽  
2021 ◽  
Author(s):  
Yusuke Matsuo ◽  
Atsuhiro Osuka ◽  
Takayuki Tanaka
Keyword(s):  
Dft Calculations ◽  
Diffraction Analysis ◽  
Strain Energy ◽  
Fluorescence Spectra ◽  
Reaction Path ◽  
Absorption And Fluorescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rigid Structure ◽  
Type Compound

Scholl reaction of ortho-phenylene-bridged cyclic pyrrole-thiophene hybrid hexamer exclusively gave a cyclophane-type compound of [5]heterohelicenes in 45% yield. The structure was unambiguously revealed by X-ray diffraction analysis. This helicenophane-type compound showed sharp absorption and fluorescence spectra, reflecting its rigid structure. The reaction path was analyzed on the basis of DFT calculations. The reaction path was analyzed on the basis of DFT calculations, and it was found that the formation of 8 is thermodynamically favored and further oxidation is prohibited due to the increased strain energy.

A flexible expanded heterocorrole: Tellura[22]porphyrin(6.1.1.0)

2019 ◽  
Vol 23 (11n12) ◽  
pp. 1470-1477
Author(s):  
Sandra Hojniak-Thyssen ◽  
Michał Szczepaniak ◽  
Lechosław Latos-Grażyński ◽  
Ewa Pacholska-Dudziak
Keyword(s):  
Nmr Spectroscopy ◽  
Dynamic Behavior ◽  
Reaction Path ◽  
Tellurium Atom ◽  
Trans Form ◽  
X Ray ◽  
Trans Studies

An expanded heterocorrole, meso-tetraaryl-tellura[22]porphyrin(6.1.1.0), containing a bipyrrole moiety and a six-carbon long link, has been synthesized. The reaction path proceeds through a controlled acid-promoted extrusion of one tellurium atom from meso-aryl-26,28-ditellurasapphyrin, leading to a structure where one tellurophene ring of the substrate is replaced by a bridging acyclic four-carbon unit. This aromatic porphyrin-annulene hybrid is conformationally flexible in solution, on account of the C4 unit adopting two different configurations: trans–cis–trans or all-trans. Studies of the dynamic behavior of tellura[22]porphyrin(6.1.1.0) in solution were performed by means of 1H and 125Te NMR spectroscopy. The X-ray structure of the all-trans form with trapezoid macrocyclic skeleton is also presented.

Structures of three lithium ester enolates by x-ray diffraction: derivation of reaction path for cleavage into ketene and alcoholate

1985 ◽  
Vol 107 (19) ◽  
pp. 5403-5409 ◽  
Author(s):  
Dieter Seebach ◽  
Rene Amstutz ◽  
Thomas Laube ◽  
W. Bernd Schweizer ◽  
J. D. Dunitz
Keyword(s):  
Reaction Path ◽  
X Ray Diffraction ◽  
X Ray

Phase Assembly of Ti2SnC Powders

2011 ◽  
Vol 412 ◽  
pp. 187-190 ◽  
Author(s):  
Chun Long Guan ◽  
Guo Qin Liu ◽  
Ying Chun Shan
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Intermetallic Compounds ◽  
Single Phase ◽  
Reaction Path ◽  
X Ray Diffraction ◽  
X Ray ◽  
Intermediate Phases ◽  
Reaction Equations ◽  
Phase Relationships

Ti2SnC powders (Ti: Sn: C =2: 1.2: 1, mol.%) were synthesized by pressureless sintering in argon in the temperature range of 600 to 1050°C using Ti, Sn and graphite powders as the initial materials. The phase relationships during reaction in the ternary system Ti-Sn-C have been investigated. The products for identification and analysis were characterized by X-ray diffraction (XRD) and differential thermal analysis (DTA). The reaction path for the formation of Ti2SnC can be described in the following steps. Sn melted at 230°C, which provided a favorable liquid circumstance for the reactions between Ti and Sn to form Ti-Sn intermetallic compounds. Results showed that Ti6Sn5 and Ti5Sn3 intermediate phases were formed in turn with increase of temperature. Up to 1050°C, with consumption of Ti5Sn3 phases completely, the amount of Ti2SnC increased significantly. Single phase Ti2SnC with small amount of TiC was produced. Combined with the results of differential thermal analysis (DTA) and X-ray diffraction (XRD), it is revealed that Ti2SnC phase is formed by the reaction of Ti–Sn intermetallic compounds, Ti and graphite. In addition, the reaction equations of the process from 230 to 1050°C were given.

Refined X-Ray Structure of the Low pH Form of Ribonuclease T1-2'-Guanylic Acid Complex at 1.9 Å Resolution1

1988 ◽  
Vol 103 (2) ◽  
pp. 354-366 ◽  
Author(s):  
Shigetoshi Sugio ◽  
Takashi Amisaki ◽  
Hirofumi Ohishi ◽  
Ken-ichi Tomita
Keyword(s):  
Low Ph ◽  
Acid Complex ◽  
Ribonuclease T1 ◽  
X Ray

Simulation of the reaction path for the nucleophilic addition >O...C?N from X-ray structural data

1993 ◽  
Vol 42 (6) ◽  
pp. 1002-1007 ◽  
Author(s):  
S. V. Konovalikhin ◽  
A. B. Zolotoi ◽  
L. O. Atovmyan
Keyword(s):  
Nucleophilic Addition ◽  
Reaction Path ◽  
Structural Data ◽  
X Ray

Single Phase Ti2AlC Powder Synthesized from Ti-Al-0.6~0.9TiC-0.1Sn Mixture

2012 ◽  
Vol 512-515 ◽  
pp. 28-31 ◽  
Author(s):  
Meng Qi Li ◽  
Hong Xiang Zhai ◽  
Zhen Ying Huang
Keyword(s):  
High Purity ◽  
Single Phase ◽  
Reaction Path ◽  
Sintering Temperature ◽  
Structure Stability ◽  
Pressureless Sintering ◽  
Ratio Scale ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

A high purity of Ti2AlC powder has been synthesized by pressureless sintering a mixture of Ti-Al-TiC-Sn (Sn as an additive) powders. Four recipes with different mole ratios of Ti-Al-TiC-Sn were examined at sintering temperature from 1400°C to 1480°C. A high purity of Ti2AlC powder can be obtained by sintering all these four recipes at temperature 1450°C for 10 min in an Ar atmosphere. The synthesis of Ti2AlC on this large mole ratio scale of starting materials is associated with the evaporation of Al at high temperature and the structure stability of Ti2AlC. From the X-ray diffraction analysis, a reaction path for the Ti2AlC formation is proposed. Scanning electron microscopy was also used to characterize the samples.

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