scholarly journals Spectrophotometric Study of Bridging N-Donor Ligand-Induced Supramolecular Assembly of Conjugated Zn-Trisporphyrin with a Triphenylamine Core

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4771
Author(s):  
Nirmal K. Shee ◽  
Ju-Won Seo ◽  
Hee-Joon Kim
Keyword(s):  
Binding Constants ◽  
Supramolecular Assembly ◽  
Spectrophotometric Titration ◽  
Spectrophotometric Study ◽  
Donor Ligands ◽  
Bridging Ligands ◽  
Donor Ligand ◽  
Bridging Ligand ◽  
Double Decker ◽  
Assembly Behavior

This article studies the supramolecular assembly behavior of a Zn-trisporphyrin conjugate containing a triphenylamine core (1) with bridging N-donor ligands using the UV-vis spectrophotometric titration method at micromolar concentrations. Our results show that pyridine, a non-bridging ligand, formed a 3:1 open complex with 1. The corresponding binding constant was estimated to be (2.7 ± 0.15) × 1014 M−3. In contrast, bridging ligands, 4,4-bipyridine (BIPY) and 1,3-di(4-pyridyl)propane (DPYP), formed stable 3:2 double-decker complexes with 1 in solution, which collapsed to yield a 3:1 open complex when excess BIPY or DPYP was added. The binding constants for forming BIPY and DPYP double-decker complexes were estimated to be (9.26 ± 0.07) × 1027 M−4 and (3.62 ± 0.16) × 1027 M−4, respectively. The UV-vis titration profiles supported the conclusion that the degradation of the 3:2 double-decker 1∙BIPY complex is less favorable compared to that of 1∙DPYP. Consequently, the formation of the 3:1 1∙DPYP open complex proceeded more readily than that of 1∙BIPY.

Aggregation-induced phosphorescent emission (AIPE) behaviors in PtII(C^N)(N-donor ligand)Cl-type complexes through restrained D2d deformation of the coordinating skeleton and their optoelectronic properties

2021 ◽  
Author(s):  
hua yang ◽  
Huiying Li ◽  
Ling Yue ◽  
Xi Chen ◽  
Dongdong Song ◽  
...  
Keyword(s):  
Optoelectronic Properties ◽  
Donor Ligands ◽  
Donor Ligand ◽  
Electrochemical Behaviors

A series of four-coordinated PtII(C^N)(N-donor ligand)Cl-type complexes have been synthesized through combination between C^N-type and N-donor ligands with different size. Photophysical features, electrochemical behaviors and electroluminescent (EL) performances have been...

Modulation of Internuclear Communication in Multinuclear Ruthenium(II) Polypyridyl Complexes

2003 ◽  
Vol 68 (8) ◽  
pp. 1467-1487 ◽  
Author(s):  
Wesley R. Browne ◽  
Frances Weldon ◽  
Adrian Guckian ◽  
Johannes G. Vos
Keyword(s):  
Ground State ◽  
Weak Interactions ◽  
Electrochemical Studies ◽  
Protonation State ◽  
Ruthenium Polypyridyl ◽  
Bridging Ligands ◽  
Polypyridyl Complexes ◽  
Bridging Ligand ◽  
Dinuclear Ruthenium ◽  
Ruthenium Polypyridyl Complexes

The syntheses and characterisation of a series of mononuclear and dinuclear ruthenium polypyridyl complexes based on the bridging ligands 1,3-bis-[5-(2-pyridyl)-1H-1,2,4-triazol-3-yl]benzene, 1,4-bis-[5-(2-pyridyl)-1H-1,2,4-triazol-3-yl]benzene, 2,5-bis-[5-(2-pyridyl)-1H-1,2,4-triazol-3-yl]thiophene, 2,5-bis-[5-pyrazinyl-1H-1,2,4-triazol-3-yl]thiophene are reported. Electrochemical studies indicate that in these systems, the ground state interaction is critically dependent on the nature of the bridging ligand and its protonation state, with strong and weak interactions being observed for thiophene- and phenylene-bridged complexes, respectively.

Synthesis and Properties of a New Kind of One-Dimensional Conductors. 1. General Aspects

1979 ◽  
Vol 34 (8) ◽  
pp. 983-985 ◽  
Author(s):  
Michael Hanack ◽  
Friedrich Franz Seelig ◽  
Joachim Strähle
Keyword(s):  
Experimental Studies ◽  
Bidentate Ligand ◽  
Central Metal Atom ◽  
Central Metal ◽  
Bridging Ligands ◽  
One Dimensional ◽  
Bridging Ligand ◽  
Linear Chains ◽  
Square Planar ◽  
General Aspects

AbstractA model for a new kind of one-dimensional conductors is presented. The compounds consist of square-planar metal complexes MX4 which are polymerised via bridging ligands L to linear chains. The bidentate ligand L, e.g. C22-, leads to the formation of a linear π-system along the chain, which is essential for the conductivity. The square-planar complex can be, for example, a metal phthalocyanine. MO-calculations show that this kind of polymer gives rise to a suitable energy band structure. An advantage of the new one-dimensional conductors is their flexibility; different combinations of the square-planar ligand system, the bridging ligand, and the central metal atom can be used. First experimental studies show that the preparation of the proposed conductors is possible.

Synthesis and characterization of two stable paramagnetic octahedral chromium(IV) complexes with dianionic tridentate SNO donor ligands and of a chromium(III) complex with a ONO donor ligand

2008 ◽  
Vol 361 (5) ◽  
pp. 1485-1495 ◽  
Author(s):  
Manjuri K. Koley ◽  
Seshadri C. Sivasubramanian ◽  
Babu Varghese ◽  
Periakaruppan T. Manoharan ◽  
Aditya P. Koley
Keyword(s):  
Donor Ligands ◽  
Synthesis And Characterization ◽  
Donor Ligand

scholarly journals Solution X-Ray Absorption Spectroscopy (XAS) for Analysis of Catalytically Active Species in Reactions with Ethylene by Homogeneous (Imido)vanadium(V) Complexes—Al Cocatalyst Systems

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1016 ◽  
Author(s):  
Kotohiro Nomura
Keyword(s):  
Active Species ◽  
Oxidation States ◽  
Donor Ligands ◽  
Ethylene Dimerization ◽  
Edge Structure ◽  
Donor Ligand ◽  
X Ray ◽  
Catalytically Active ◽  
Type V ◽  
X Ray Absorption

Solution V K-edge XANES (X-ray absorption near edge structure) and EXAFS (extended X-ray absorption fine structure) analysis of vanadium(V) complexes containing both imido ligands and anionic ancillary donor ligands (L) of type, V(NR)(L)X2 (R = Ar, Ad (1-adamantyl); Ar = 2,6-Me2C6H3; X = Cl, Me, L = 2-(ArNCH2)C5H4N, OAr, WCA-NHC, and 2-(2’-benzimidazolyl)pyridine; WCA-NHC = anionic NHCs containing weak coordinating B(C6F5)3), which catalyze ethylene dimerization and/or polymerization in the presence of Al cocatalysts, has been explored. Different catalytically actives species with different oxidation states were formed depending upon the Al cocatalyst (MAO, Me2AlCl, AliBu3, etc.) and the anionic ancillary donor ligand employed. The method is useful for obtainment of the direct information of the active species (oxidation state, basic framework around the centered metal) in solution, and for better understanding in catalysis mechanism and organometallic as well as coordination chemistry.

Long range antiferromagnetic exchange in dinuclear copper(II) complexes containing 1,4-dicyanamidobenzene dianion bridging ligands

1995 ◽  
Vol 73 (4) ◽  
pp. 573-580 ◽  
Author(s):  
Linnus L. Cheruiyot ◽  
Robert J. Crutchley ◽  
Laurence K. Thompson ◽  
J.E. Greedan ◽  
Guo Liu
Keyword(s):  
Magnetic Susceptibility ◽  
Elemental Analysis ◽  
Epr Spectroscopy ◽  
Antiferromagnetic Exchange ◽  
Temperature Dependent ◽  
Magnetic Studies ◽  
Bridging Ligands ◽  
Dimer Model ◽  
Bridging Ligand ◽  
Exchange Constants

Six Cu(II)dimers, [{Cu(dien)}2(μ-dicyd)][CF3SO3]2 (1), [{Cu(dien)}2(μ-Me2dicyd)][CF3SO3]2 (2), [{Cu(dien)}2(μ-Cl2dicyd)][CF3SO3]2 (3), [{Cu(L)}2(μ-dicyd)] (4), [{Cu(L)}2(μ-Me2dicyd)] (5), and [{Cu(L)}2(μ-Cl2dicyd)] (6), where dicyd2−, Me2dicyd2− and Cl2dicyd2− are unsubstituted, 2,5-dimethyl- and 2,5-dichloro-1,4-dicyanamidobenzene dianions, respectively, dien is diethylenetriamine, and L− = 1,3-bis(2-pyridylimino)isoindolinato, have been synthesized and characterized by elemental analysis, IR, UV–vis, and EPR spectroscopy, and magnetic studies. Temperature-dependent magnetic susceptibility measurements of the complexes 1–6 from 5 to 300 K are reported. The data for 2, 3, 5, and 6 have been fitted to a dimer model with a modified Bleaney–Bowers expression which derived antiferromagnetic exchange constants −J = 10.6, 4.5, 5.2, and 3.0 cm−1, respectively (where the Hamiltonian is of the form [Formula: see text]) For 4, an approach to a maximum in χm with decreasing temperature gave an estimated −J < 3.5 cm−1. Only complex 1 showed Curie–Weiss behavior. This is far weaker antiferromagnetic exchange compared to that observed for dinuclear Ru(III) complexes incorporating the dicyd2− bridging ligands (J. Am. Chem Soc. 114, 5130 (1992)) and is attributed to a symmetry and energy mismatch between Cu(II) σ* magnetic orbitals and the πnb molecular orbitals of the bridging ligand which are important for superexchange. Keywords: superexchange, copper dimer, dicyanamidobenzene.

Intramolecular Hydroamination of Aminoalkenes using Rhodium(I) and Iridium(I) Complexes with N,N- and P,N-Donor Ligands

2011 ◽  
Vol 64 (6) ◽  
pp. 741 ◽  
Author(s):  
Thi O. Nguyen ◽  
Bradley Y.-W. Man ◽  
Richard Hodgson ◽  
Barbara A. Messerle
Keyword(s):  
Donor Ligands ◽  
Donor Ligand

Cationic rhodium(i) and iridium(i) complexes containing the bidentate heterocyclic N,N-donor ligand bis(1-pyrazolyl)methane (bpm) and the counterion tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BArF–) were found to be efficient catalysts for the cyclization of activated and unactivated aminoalkenes. The rates of cyclization were found to be highly dependent upon the size and steric bulk of the substituents at the γ-position of the aminoalkene, with large steric bulk leading to faster rates of cyclization. In comparison, analogous rhodium(i) and iridium(i) complexes with the mixed P,N-donor ligand 1-[2-(diphenylphosphino)ethyl]pyrazole (PyP) were found to be less effective as catalysts for this reaction.

Crystal structures, topological analysis and luminescence properties of three coordination polymers based on a semi-rigid ligand and N-donor ligand linkers

2016 ◽  
Vol 40 (7) ◽  
pp. 5957-5965 ◽  
Author(s):  
Xiaobin Liu ◽  
Zhenyu Xiao ◽  
Ao Huang ◽  
Wen Wang ◽  
Liangliang Zhang ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Coordination Polymers ◽  
Topological Analysis ◽  
Mixed Ligand ◽  
Donor Ligands ◽  
Luminescence Properties ◽  
Donor Ligand ◽  
Ligand Coordination

Three new mixed-ligand coordination polymers have been synthesized based on 3,3′-(anthracene-9,10-diyl)diacrylate acid and different N-donor ligands. Complex 2 displays rapid and selective sensing of Fe3+.

scholarly journals SPECTROPHOTOMETRIC STUDY OF ACID-BASE PROPERTIES OF SPATIAL-DISTORTED DERIVATIVES OF PORPHYRINS IN ACETONITRILE

2018 ◽  
Vol 59 (6) ◽  
pp. 49 ◽  
Author(s):  
Yulia B. Ivanova ◽  
Svetlana G. Puhovskaya ◽  
Nugzar Zh. Mamardashvili ◽  
Oscar I. Koifman
Keyword(s):  
Absorption Spectra ◽  
Molecular Form ◽  
Spectral Characteristics ◽  
Reaction System ◽  
Spectrophotometric Titration ◽  
Spectrophotometric Study ◽  
Acidic Properties ◽  
Acid Base ◽  
Electron Absorption ◽  
Base Properties

Spectrophotometric titration method was used to study the acidic properties of: 5,10,15,20-tetrakis(thienyl-2-yl)-2,3,7,8,12,13,17,18-octaethylporphyrin (I), 5,10,15,20-tetrakis(4’-t-butylphenyl)-2,3,7,8,12,13,17,18-octaethylporphyrin (II), 5,10,15,20-tetrakis(3,5-di-t-butylphe-nyl)-2,3,7,8,12,13,17,18-octaethylporphyrin (III), 5,10,15,20-tetraphenyl-2,3,7,8,12,13,17,18-octaethylporphyrin (IV), 5,15-bis(4’-methoxyphenyl)-10,20-bis(4-nitro-phenyl)-2,8,12,18-tetrame-thyl-3,7,13,17-tetraarylporphyrin (V), 5,15-bis(4’-methoxyphenyl)-10,20-diphenyl-2,3,7,8,12,13, 17,18-octaethylporphyrin (VI), 5,15-bis(4’-methoxyphenyl)-2,8,12,18-tetramethyl-3,7,10,13,17,20-hexaethylporphin (VII), 5,10,15,20-tetrakis(4’-methoxyphenyl)-2,3,7,8,12,13,17,18-octaethylpor-phyrin (VIII) in the presence of a deprotonated agent, 1,8-diazabicyclo[5.4.0] undec-7-ene, in acetonitrile. Under deprotonation two families of spectral curves in the absorption spectra, having its own system of isobestic points, are formed. Electron absorption spectrum of molecular form transforms gradually into the spectrum of the final form of dianion with titrant concentration increase. Determination of the coordinates of the inflection (and the corresponding concentration of DBU) on the titration curve  allowed us to distinguish two areas in the electron absorption spectra of the reaction system, which are likely belong to the first and second steps of deprotonation, namely, to the formation of mono- and dianionic forms (HP–  and P2–) of the compound. Spectral characteristics of the ionized forms and combined ionization constant for the first and second steps (lgКа1 and lgКа2) were revealed. At the first step in the order of decreasing acidic properties of the ligands the compounds form a series of: III< V< VIII< VI < VII< II< IV < I; at the second step in decreasing order of the acidic properties of the ligands the compounds form a series of:.III < V < VI < II <VIII< VII < IV < I. The effect of structural and electronic properties of substituents on acid-base properties of porphyrins is analyzed. Thus, chemical modification of the macrocycle can lead to direct changes in acid-base properties of supramolecular macroheterocyclic ligands and can be a powerful tool to control the reactivity of compounds of the porphyrins class.

Amino(keto)carbene und Amino(phenyl)carbene als 1.4-dipolare Brückenliganden in einer Fe2(CO)6-Matrix / Amino(keto)carbenes and Amino(phenyl)carbenes as 1,4-Dipolar Bridging Ligands in a Fe2(CO)6 Matrix

1983 ◽  
Vol 38 (11) ◽  
pp. 1325-1331 ◽  
Author(s):  
Rudolf Aumann ◽  
Heinrich Heinen ◽  
Gerald Henkel ◽  
Mechtild Dartmann ◽  
Bernt Krebs
Keyword(s):  
Crystal Structure ◽  
Phenyl Group ◽  
Crystal Structure Analysis ◽  
Function Form ◽  
Group Vi ◽  
Bridging Ligands ◽  
Carbene Complexes ◽  
Phenyl Derivative ◽  
Bridging Ligand ◽  
Single Crystal Structure Analysis

AbstractCyclohexylamino(keto)carbene complexes of group VI B metals which contain a terminally bound carbene ligand, on reaction with Fe2(C0)9 give binuclear oxallyl iron complexes 5, in which the carbene carbon and the keto function form a bridge consisting of three atoms bound to two iron atoms. From a single crystal structure analysis of the phenyl derivative 5b, the Fe-Fe distance was found to be 2.508 Å. The two C atoms are bridging the Fe2 group in a somewhat distorted manner (C(l)-Fe(l) 2.461, C(l)-Fe(2) 1.912, C(2)-Fe(l) 2.024, C(2)-Fe(2) 2.478 Å), whereas the bridging keto oxygen is symmetrically bound to both Fe (1.927 and 2.004 Å). Alkylamino(phenyl)carbene complexes like 11 react with Fe2(C0)9 to give a four atom bridging ligand by migration of a hydrogen atom from nitrogen and an ortho hydrogen from the phenyl group to the carbene carbon. Free or complexed alkylimines may be intermediates in this reaction.

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