The synthesis and metal binding chemistry of carbahemiporphyrazines with an electron withdrawing substituent

2012 ◽  
Vol 16 (02) ◽  
pp. 175-182 ◽  
Author(s):  
Roshinee Costa ◽  
James T. Engle ◽  
Christopher J. Ziegler
Keyword(s):  
Metal Binding ◽  
Structural Features ◽  
Bond Lengths ◽  
Benzene Rings ◽  
Metal Adducts

Benziphthalocyanine (bzpc) and dicarbahemiporphyrazine (dchp) are phthalocyanine analogs where one and two of the isoindoline units have been replaced with benzene rings. In this report, we present dchp and bzpc analogs 1 and 2 where CF3 groups have been placed on the 5-position of the benzene rings. Compounds 1 and 2 have identical structural features as their unmodified parent macrocycles, but some differences are observed in their metal adducts. Complex 1Ag shows few differences with the analogous dchp complex, but compounds 1Cu and 2Co exhibit reductions in M – C bond lengths arising from the electron withdrawing nature of the CF3 unit.

scholarly journals Diphenyl[(phenylsulfanyl)methyl]-λ5-phosphanethione

2014 ◽  
Vol 70 (3) ◽  
pp. o374-o374
Author(s):  
Viktoria H. Gessner
Keyword(s):  
Crystal Structure ◽  
Dihedral Angle ◽  
Intermolecular Interactions ◽  
Title Compound ◽  
Subsequent Reaction ◽  
Bond Lengths ◽  
Compound C ◽  
Benzene Rings ◽  
Diphenyl Disulfide

The title compound, C19H17PS2, results from the direct deprotonation of diphenylmethylphosphine sulfide and subsequent reaction with diphenyl disulfide. The C—P and C—S bond lengths of 1.8242 (18) and 1.8009 (18) Å, respectively, of the central P—C—S linkage are comparable to those found in the sulfonyl analogue, but are considerably longer than those reported for the dimetallated sulfonyl compound. The dihedral angle between the benzene rings of the diphenylmethyl moiety is 69.46 (7)°. No distinct intermolecular interactions are present in the crystal structure.

scholarly journals (E)-1-(4-Chlorophenyl)-3-(4-methoxyphenyl)prop-2-en-1-one

2006 ◽  
Vol 62 (4) ◽  
pp. o1627-o1628 ◽  
Author(s):  
Xiao-Yang Qiu ◽  
Sen-Lin Yang ◽  
Wei-Sheng Liu ◽  
Hai-liang Zhu
Keyword(s):  
Dihedral Angle ◽  
Normal Values ◽  
Crystal Packing ◽  
Van Der Waals ◽  
Van Der Waals Forces ◽  
Bond Lengths ◽  
Benzene Rings ◽  
Title Molecule

In the title molecule, C16H13ClO2, all bond lengths and angles show normal values. The two benzene rings make a dihedral angle of 21.0 (4)°. The crystal packing is stabilized by van der Waals forces.

scholarly journals A trapped human PPM1A–phosphopeptide complex reveals structural features critical for regulation of PPM protein phosphatase activity

2018 ◽  
Vol 293 (21) ◽  
pp. 7993-8008 ◽  
Author(s):  
Subrata Debnath ◽  
Dalibor Kosek ◽  
Harichandra D. Tagad ◽  
Stewart R. Durell ◽  
Daniel H. Appella ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Metal Ions ◽  
Active Site ◽  
Metal Binding ◽  
Metal Ion ◽  
Catalytic Domain ◽  
Protein Phosphatases ◽  
Random Order ◽  
Structural Features

Metal-dependent protein phosphatases (PPM) are evolutionarily unrelated to other serine/threonine protein phosphatases and are characterized by their requirement for supplementation with millimolar concentrations of Mg2+ or Mn2+ ions for activity in vitro. The crystal structure of human PPM1A (also known as PP2Cα), the first PPM structure determined, displays two tightly bound Mn2+ ions in the active site and a small subdomain, termed the Flap, located adjacent to the active site. Some recent crystal structures of bacterial or plant PPM phosphatases have disclosed two tightly bound metal ions and an additional third metal ion in the active site. Here, the crystal structure of the catalytic domain of human PPM1A, PPM1Acat, complexed with a cyclic phosphopeptide, c(MpSIpYVA), a cyclized variant of the activation loop of p38 MAPK (a physiological substrate of PPM1A), revealed three metal ions in the active site. The PPM1Acat D146E–c(MpSIpYVA) complex confirmed the presence of the anticipated third metal ion in the active site of metazoan PPM phosphatases. Biophysical and computational methods suggested that complex formation results in a slightly more compact solution conformation through reduced conformational flexibility of the Flap subdomain. We also observed that the position of the substrate in the active site allows solvent access to the labile third metal-binding site. Enzyme kinetics of PPM1Acat toward a phosphopeptide substrate supported a random-order, bi-substrate mechanism, with substantial interaction between the bound substrate and the labile metal ion. This work illuminates the structural and thermodynamic basis of an innate mechanism regulating the activity of PPM phosphatases.

Nickel-responsive transcriptional regulators

Metallomics ◽  
2015 ◽  
Vol 7 (9) ◽  
pp. 1305-1318 ◽  
Author(s):  
Francesco Musiani ◽  
Barbara Zambelli ◽  
Micaela Bazzani ◽  
Luca Mazzei ◽  
Stefano Ciurli
Keyword(s):  
Metal Binding ◽  
Transcriptional Regulators ◽  
Structural Features ◽  
Metal Coordination ◽  
Coordination Modes ◽  
Binding Thermodynamics

The structural features, metal coordination modes and metal binding thermodynamics of known Ni(ii)-dependent transcriptional regulators are highlighted and discussed.

scholarly journals Crystal structure ofN-[3-(dimethylamino)propyl]-N′,N′,N′′,N′′-tetramethyl-N-(N,N,N′,N′-tetramethylformamidiniumyl)guanidinium bis(tetraphenylborate)

2015 ◽  
Vol 71 (12) ◽  
pp. o1045-o1046 ◽  
Author(s):  
Ioannis Tiritiris ◽  
Willi Kantlehner
Keyword(s):  
Crystal Structure ◽  
Double Bond ◽  
Dihedral Angle ◽  
Two Dimensional ◽  
Double Bond Character ◽  
Bond Lengths ◽  
Π Interactions ◽  
Benzene Rings ◽  
Bond Character

In the title salt, C15H36N62+·2C24H20B−, the three N—C bond lengths in the central C3N unit of the bisamidinium ion range between 1.388 (3) and 1.506 (3) Å, indicating single- and double-bond character. Furthermore, four C—N bonds have double-bond character. Here, the bond lengths range from 1.319 (3) to 1.333 (3) Å. Delocalization of the positive charges occurs in the N/C/N and C/N/C planes. The dihedral angle between both N/C/N planes is 70.5 (2)°. In the crystal, C—H...π interactions between H atoms of the cation and the benzene rings of both tetraphenylborate ions are present. The benzene rings form aromatic pockets, in which the bisamidinium ion is embedded. This leads to the formation of a two-dimensional supramolecular pattern along theabplane.

Polyfluorinated ligand-supported organometallic complexes of copper, silver, and gold

2010 ◽  
Vol 82 (3) ◽  
pp. 649-656 ◽  
Author(s):  
H. V. Rasika Dias
Keyword(s):  
Structural Features ◽  
Organometallic Complexes ◽  
Crystalline Solids ◽  
Coinage Metal ◽  
Coinage Metals ◽  
Metal Adducts

The tris(pyrazolyl)borate [HB(3,5-(CF3)2Pz)3]− prepared using highly fluorinated 3,5-bis(trifluoromethyl)pyrazole and BH4− is an excellent supporting ligand for the stabilization of a number of rare organometallic complexes of coinage metals. For example, it has enabled the isolation of Cu(I), Ag(I), and Au(I) complexes of CO and ethylene as crystalline solids. Syntheses, spectroscopic and structural features, and properties of [HB(3,5-(CF3)2Pz)3]ML (M = Cu, Ag, Au; L = CO, C2H4) are the main focus of this discussion. Several metal adducts based on the tris(triazolyl)borate [HB(3,5-(CF3)2Tz)3]− supporting ligand as well as the cationic, coinage metal multi-alkene complexes containing the [SbF6]− counterion are also discussed.

scholarly journals The Coordination Chemistry of Imidomethanedithiolate Di-anions: A Structural Comparison with Their Dithiocarbamate Analogs

Inorganics ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 71
Author(s):  
Peter J. Heard ◽  
Yee Seng Tan ◽  
Chien Ing Yeo ◽  
Edward R. T. Tiekink
Keyword(s):  
Coordination Chemistry ◽  
Heavy Element ◽  
Structural Features ◽  
Structural Comparison ◽  
Structural Motifs ◽  
Bond Lengths ◽  
Heavy Element Complexes

A review of the coordination chemistry along with the structural features of heavy element complexes of dithiocarbimate di-anions in the form of [(R)C=NCS2]2− for R = CN, alkyl, and aryl are described. This class of compound is far less studied compared with the well-explored dithiocarbamate mono-anions formulated as [R(R’)NCS2]− for R/R’ = H, alkyl, and aryl. The coordination chemistry of dithiocarbimate di-anions is dominated by a S,S-chelating mode; rare examples of alternative modes of coordination are evident. When comparisons are available, the structural motifs adopted by metal dithiocarbimate complexes match those found for their dithiocarbamate analogs, with only small, non-systematic variations in the M–S bond lengths.

Metallothionein: Protein structure prediction and sequence analyses in pigeon pea(Cajanuscajan)

2017 ◽  
Vol 4 (04) ◽  
Author(s):  
Sakshi Chaudhary ◽  
Anil Kumar Singh ◽  
Jeshima Khan Yasin
Keyword(s):  
Protein Structure ◽  
Metal Binding ◽  
Structure Prediction ◽  
Structural Similarity ◽  
Pigeon Pea ◽  
Structural Features ◽  
Structural Domain ◽  
Small Proteins ◽  
Heavy Metal Binding ◽  
Entire Sequence

Metallothioneins are a special group of small proteins capable of detoxifying non-essential metal ions present in excess within a plant cell. Metallothioneins are cysteine-rich diverse classes of heavy metal binding protein molecules which are essential for plant growth.These proteins are present in all taxa, except eubacteria. The similarity in protein sequences provides a basis for the method which predicts structural features of a protein with that of a known protein structure. Structural similarity of entire sequence or large sequence fragment enables prediction and modeling of entire structural domain, while distribution of local features of known protein structure make it possible to predict such features in structure of unknown or uncharacterised proteins.In this study, from available genomic resources metallothionein of pigeonpea was identified, structure of metallothionein was predicted and validated. We have presented a step-wise methodology to model a given protein and to validate the structures.

scholarly journals The structure of polyisoprenes. VI An investigation of the molecular structure of dibenzyl by X-ray analysis

1947 ◽  
Vol 188 (1013) ◽  
pp. 222-236 ◽  
Keyword(s):  
Molecular Structure ◽  
Standard Length ◽  
Three Dimensional ◽  
Intermolecular Forces ◽  
The Other ◽  
X Ray ◽  
Bond Lengths ◽  
Benzene Rings ◽  
Carbon Bonds ◽  
Atomic Parameters

The molecular structure of dibenzyl has been determined to an accuracy of about 0.01A by using extensive X-ray data in three-dimensional Fourier syntheses to refine the approximate atomic parameters originally derived by Robertson. The three formally single-carbon bonds joining the benzene rings have lengths of 1.50, 1.48 and 1.50A and make angles of 115° with each other. The departure from the standard length of 1.54A is discussed in relation to the analogous systems of polyisoprenes and 1.5 dienes where related effects have been observed. The dimensions of the benzene rings also reflect the unusual character of the acyclic carbon bonds, two of the aromatic bond lengths being 1.39A and the other four 1.37A. The molecule, although possessing a centre of symmetry, is not absolutely symmetrical, since the central CH 2 — CH 2 bond is inclined at 70.5° to the plane of the benzene rings. This is ascribed to the influence of intermolecular forces.

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