New transition metal binding modes for creatinine: molecular structures of [(C4R4)Ir(C4H7N3O)(PPh3)2Cl] and [(C4R4)Ir(C4H7N3O)(PPh3)2]BF4, (R = CO2CH3)

Polyhedron ◽  
1997 ◽  
Vol 16 (12) ◽  
pp. 2029-2035 ◽  
Author(s):  
Joseph M. O'Connor ◽  
Kristin Hiibner ◽  
Arnold L. Rheingold ◽  
Louise M. Liable-Sands
Keyword(s):  
Transition Metal ◽  
Metal Binding ◽  
Molecular Structures ◽  
Binding Modes

High-resolution electron spectroscopy and molecular structures of Cu–(2,2′-bipyridine) and Cu-(4,4′-bipyridine)

2013 ◽  
Vol 91 (7) ◽  
pp. 613-620 ◽  
Author(s):  
Xu Wang ◽  
Jung Sup Lee ◽  
Dong-Sheng Yang
Keyword(s):  
Ground State ◽  
Metal Binding ◽  
Electron Spectroscopy ◽  
Density Functional ◽  
Copper Complexes ◽  
Theoretical Calculations ◽  
Molecular Structures ◽  
Laser Vaporization ◽  
Binding Modes ◽  
Mp2 Calculations

Copper complexes of 2,2′-bipyridine (22BIPY) and 4,4′-bipyridine (44BIPY) were prepared in a laser-vaporization supersonic molecular beam source and identified by laser photoionization time-of-flight mass spectrometry. Electronic spectra and molecular structures were studied with pulsed-field ionization zero electron kinetic energy (ZEKE) electron spectroscopy, density functional theory (DFT) and second-order Møller–Plesset perturbation (MP2) calculations, and spectral simulations. Adiabatic ionization energies and metal–ligand and ligand-based vibrational frequencies of Cu–22BIPY and Cu–44BIPY were measured from the ZEKE spectra. Ground electronic states and molecular structures of the two complexes were determined by comparing the spectroscopic measurements with the theoretical calculations. The ground state of Cu–22BIPY ( 2 B1, C2v) has a planar bidentate structure with Cu binding to two nitrogen atoms and two pyridine molecules in the cis configuration. The ground state of Cu–44BIPY ( 2 A, C2) has a monodentate structure with Cu binding to one nitrogen and two pyridines in a twisted configuration. The ionization energy of Cu–22BIPY is considerably lower and its bond energy is much higher than that of Cu–44BIPY. The different ionization and dissociation energies are attributed to the distinct metal binding modes of the two complexes. It has been found that the DFT calculations yield the correct structures for the Cu–22BIPY complex, whereas the MP2 calculations produce the best structures for the Cu–44BIPY complex.

scholarly journals 1,3,5-Triaza-7-Phosphaadamantane (PTA) as a 31P NMR Probe for Organometallic Transition Metal Complexes in Solution

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1390 ◽  
Author(s):  
Ilya G. Shenderovich
Keyword(s):  
Chemical Shift ◽  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Density Functional ◽  
Molecular Structures ◽  
Basis Sets ◽  
Functional Theory ◽  
Non Covalent Interactions ◽  
Covalent Interactions

Due to the rigid structure of 1,3,5-triaza-7-phosphaadamantane (PTA), its 31P chemical shift solely depends on non-covalent interactions in which the molecule is involved. The maximum range of change caused by the most common of these, hydrogen bonding, is only 6 ppm, because the active site is one of the PTA nitrogen atoms. In contrast, when the PTA phosphorus atom is coordinated to a metal, the range of change exceeds 100 ppm. This feature can be used to support or reject specific structural models of organometallic transition metal complexes in solution by comparing the experimental and Density Functional Theory (DFT) calculated values of this 31P chemical shift. This approach has been tested on a variety of the metals of groups 8–12 and molecular structures. General recommendations for appropriate basis sets are reported.

Structural and spectroscopic studies of transition metal nitrite complexes. VIII. Crystal structures and spectra of three pentanuclear species with stoichiometry [Ni5(N-substituted ethane-1,2-diamine)4(OH)2(NO2)8]

1981 ◽  
Vol 34 (10) ◽  
pp. 2139 ◽  
Author(s):  
AJ Finney ◽  
MA Hitchman ◽  
CL Raston ◽  
GL Rowbottom ◽  
AH White
Keyword(s):  
Transition Metal ◽  
Crystal Structures ◽  
General Formula ◽  
Infrared Spectra ◽  
Spectroscopic Studies ◽  
Molecular Structures ◽  
Structural Variations ◽  
Crystal And Molecular Structures

The preparation of a series of novel compounds of general formula [Ni5L4(NO2)8(OH)2] formed by ethane-1,2-diamine or one of five N-substituted ethane-1,2-diamines (L) is described. The crystal and molecular structures of the ethane-1,2-diamine, N,N'-diethylethane-1,2-diamine and N,N-dimethylethane-1,2-diamine complexes are reported. Each compound contains a planar, pentameric arrangement of nickel(II) ions, linked by bridging hydroxide and nitrite ligands. The details of the nitrite bridges differ among the complexes, causing differences in their electronic and infrared spectra. The structural variations are probably caused by the differing steric requirements of the amine substituents.

Structural and spectroscopic studies of transition metal nitrite complexes. V. Crystal structures and spectra of trans-Tetrakis(pyridine)dinitritonickel(II)-pyridine (1/2), trans-Tetrakis(4-methylpyridine)dinitritonickel(II) and trans-Tetrakis(pyrazole)-dinitritonickel(II)

1981 ◽  
Vol 34 (10) ◽  
pp. 2095 ◽  
Author(s):  
AJ Finney ◽  
MA Hitchman ◽  
CL Raston ◽  
GL Rowbottom ◽  
BW Skelton ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Transition Metal ◽  
Crystal Structures ◽  
Electronic Spectra ◽  
Spectroscopic Studies ◽  
Molecular Structures ◽  
Aromatic Rings ◽  
Paddle Wheel ◽  
Crystal And Molecular Structures ◽  
Infrared Frequencies

The crystal and molecular structures of the compounds [Ni(py)4(ONO)2],2py, [Ni(γmpy),(ONO)2] and [Ni(prz)4(ONO)2] are reported.�All three are trans nitrito complexes, the pyridine (py) compound containing two pyridine molecules of solvation. The aromatic rings in the first two complexes adopt 'paddle wheel' conformations with pitch angles varying between 40 and 70�. The nitrite ions are positioned so as to minimize repulsive interactions with the amines, and it seems likely that these groups bond through oxygen rather than nitrogen because this allows a lesser degree of interligand steric interference. The amine rings in [Ni(prz)4(ONO)2] are orthogonal to the plane containing the nickel and coordinated pyrazole nitrogen atoms; the nitrito groups are disordered between two inequivalent positions, each of which involves hydrogen bonding with the pyrazole NH groups. The nitrite infrared frequencies are similar to those observed for other nickel(II) nitrito complexes except that the antisymmetric NO stretching mode of one of the groups in the pyrazole complex is much lower in energy than expected, being in the range normally associated with a nitrogen-bonded or chelated nitrite group. It is suggested that this deviation may be caused by the hydrogen bonding in the complex. The electronic spectra of the compounds yield 10Dq values of 9100 and 8500 cm-1 for the nitrite ligands in [Ni(py)4(ONO)2] and Ni(prz)4(ONO)2], respectively, placing the nitrito group towards the weaker end of the spectro-chemical series.

scholarly journals Dissimilar Ligands Bind in a Similar Fashion: A Guide to Ligand Binding-Mode Prediction with Application to CELPP Studies

2021 ◽  
Vol 22 (22) ◽  
pp. 12320
Author(s):  
Xianjin Xu ◽  
Xiaoqin Zou
Keyword(s):  
Molecular Similarity ◽  
Complex Structure ◽  
Binding Mode ◽  
Molecular Structures ◽  
Complex Structures ◽  
Binding Modes ◽  
Ligand Complex ◽  
Systematic Analysis ◽  
Binding Mode Prediction ◽  
Similarity Principle

The molecular similarity principle has achieved great successes in the field of drug design/discovery. Existing studies have focused on similar ligands, while the behaviors of dissimilar ligands remain unknown. In this study, we developed an intercomparison strategy in order to compare the binding modes of ligands with different molecular structures. A systematic analysis of a newly constructed protein–ligand complex structure dataset showed that ligands with similar structures tended to share a similar binding mode, which is consistent with the Molecular Similarity Principle. More importantly, the results revealed that dissimilar ligands can also bind in a similar fashion. This finding may open another avenue for drug discovery. Furthermore, a template-guiding method was introduced for predicting protein–ligand complex structures. With the use of dissimilar ligands as templates, our method significantly outperformed the traditional molecular docking methods. The newly developed template-guiding method was further applied to recent CELPP studies.

Übergangsmetallkomplexe mit Schwefelliganden, LXXIII. Diastereospezifische Dichlormethylierung schwefelreicher [RuII(SRR′)(PPh3)′S4]-Komplexe (SRR′ = einzähniger Thioether- oder Thiol-Ligand; ′S4′2- = 1,2-Bis(2-mercaptophenylthio)ethan(2-)) / Transition Metal Complexes with Sulfur Ligands, LXXIII. Diastereospecific Dichloromethylation of Sulfur Rich [RuII(SRR′)(PPh3)′S4] Complexes (SRR′ = Monodentate Thioether or Thiol Ligand;′S4′2- = 1,2-Bis(2-mercaptophenylthio)ethane(2-))

1991 ◽  
Vol 46 (12) ◽  
pp. 1585-1592 ◽  
Author(s):  
Dieter Sellmann ◽  
Peter Lechner ◽  
Falk Knoch ◽  
Matthias Moll
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Molecular Structures ◽  
X Ray ◽  
X Ray Crystallography ◽  
Thiol Ligand

Under exclusion of air the thioether and thiol complexes [Ru(SRR′)(PPh3)′S4′] (′S4′2- = 1,2-bis(2-mercaptophenylthio)ethane (2—)) easily react with CHCl3 yielding [Ru(Cl)(PPh3)(′S4′—CHCl2)] in which one thiolato atom of the ′S4′ ligand is diastereospecifically dichloromethylated. In the presence of air, however, [RuIII(Cl)(PPh3)′S4′] is formed.The molecular structures of [Ru(Cl)(PPh3)(′S4′-CHCl2)] · 2CHCl3 and [RuIII(Cl)(PPh3)′buS4′] have been determined by X-ray crystallography. ′buS4′2- (= 1,2-bis(3,5-di(t-butyl)-2-mercaptophenylthio)ethane(2-)) is the t-butyl derivative of the ′S4′ ligand. Reasons for observed diastereospecifity of alkylation are discussed.

Unravelling the versatile metal binding modes of adenine: Looking at the molecular recognition patterns of deaza- and aza-adenines in mixed ligand metal complexes

2013 ◽  
Vol 257 (19-20) ◽  
pp. 2814-2838 ◽  
Author(s):  
Alicia Domínguez-Martín ◽  
María del Pilar Brandi-Blanco ◽  
Antonio Matilla-Hernández ◽  
Hanan El Bakkali ◽  
Valeria Marina Nurchi ◽  
...  
Keyword(s):  
Molecular Recognition ◽  
Metal Complexes ◽  
Metal Binding ◽  
Mixed Ligand ◽  
Binding Modes

scholarly journals Structure and Metal Binding Properties of Chlamydia trachomatis YtgA

2019 ◽  
Vol 202 (1) ◽  
Author(s):  
Zhenyao Luo ◽  
Stephanie L. Neville ◽  
Rebecca Campbell ◽  
Jacqueline R. Morey ◽  
Shruti Menon ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Transition Metal ◽  
Metal Binding ◽  
Developed Countries ◽  
Biochemical Properties ◽  
Host Cells ◽  
Transmitted Infection ◽  
Content Type ◽  
Sexually Transmitted ◽  
Serious Disease

Chlamydia trachomatis is the most common bacterial sexually transmitted infection in developed countries, with an estimated global prevalence of 4.2% in the 15- to 49-year age group. Although infection is asymptomatic in more than 80% of infected women, about 10% of cases result in serious disease. Infection by C. trachomatis is dependent on the ability to acquire essential nutrients, such as the transition metal iron, from host cells. In this study, we show that iron is the most abundant transition metal in C. trachomatis and report the structural and biochemical properties of the iron-recruiting protein YtgA. Knowledge of the high-resolution structure of YtgA will provide a platform for future structure-based antimicrobial design approaches.

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