scholarly journals Mössbauer study of some novel iron-bis-glyoxime and iron-tris-glyoxime complexes

2021 ◽  
Vol 243 (1) ◽  
Author(s):  
Cs. Várhelyi ◽  
Z. Homonnay ◽  
R. Szalay ◽  
Gy. Pokol ◽  
I-M. Szilágyi ◽  
...  
Keyword(s):  
Mass Spectroscopy ◽  
High Volume ◽  
Chemical Processes ◽  
Mössbauer Study ◽  
Alkyl Chains ◽  
Donor Acceptor ◽  
Analytical Reagents ◽  
State 1 ◽  
Long Chain ◽  
High Spin Iron

AbstractDioximes as ligands are used as analytical reagents and serve as models for biological systems as well as catalysts in chemical processes. A number of novel mixed complexes of the type [Fe(DioxH)2(amine)2] have been prepared and characterised by FTIR, 57Fe Mössbauer and mass spectroscopy by us. We have found strong Fe–N donor acceptor interactions and iron occurred in low-spin FeII state in all complexes. Later, we have also found that the incorporation of branching alkyl chains (isopropyl) in the complexes alters the Fe–N bond length and results in high-spin iron(II) state [1, 2]. The question arises: can the spin state of iron be manipulated generally by replacing the short alkyl chains with high volume demand ones in Fe-azomethine-amine complexes? To answer the question we have synthetized novel iron-bis-glioxime and iron-tris-gloxime complexes when long chain alkyl or aromatic ligands replaced the short alkyl ones and studied by 57Fe Mössbauer spectroscopy, MS, FTIR, UV-VIS, TG-DTA-DTG and XRD methods. Novel iron-bis-glyoxime and iron-tris-glyoxime type complexes, [Fe(Diethyl-Diox)3(BOH)2], [Fe(Diethyl-Diox)3(BOEt)2] and [Fe(phenyl-Me-Diox)3(BOEt)2], were synthesized similarly as described in [2]. The FTIR, UV-VIS, TG-DTA-DTG and MS measurements indicated that the expected novel complexes could be successfully synthesized.

Spin-crossover iron(II) long-chain complex with slow spin equilibrium at low temperature

2021 ◽  
Author(s):  
Qi Zhao ◽  
Jin-Peng Xue ◽  
Zhi-Kun Liu ◽  
Zi-Shuo Yao ◽  
Jun Tao
Keyword(s):  
Low Temperature ◽  
Single Crystal ◽  
Spin Crossover ◽  
Chain Complex ◽  
Mononuclear Complex ◽  
X Ray ◽  
Alkyl Chains ◽  
Long Chain

A mononuclear complex with long alkyl chains, [FeII(H2Bpz2)2(C9bpy)] (1; H2Bpz2 = dihydrobis(1-pyrazolyl)borate, C9bpy = 4,4'-dinonyl-2,2'-bipyridine), was synthesized. Single-crystal X-ray crystallographic studies revealed that - and - forms of the complex...

Dipole moments induced in larger molecule. Long-chain aliphatic esters

1982 ◽  
Vol 47 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Otto Exner ◽  
Ayfer Bapçum
Keyword(s):  
Benzene Solution ◽  
Dipole Moments ◽  
Straight Chain ◽  
Basic Assumptions ◽  
Donor Acceptor ◽  
Eyring Theory ◽  
Aliphatic Esters ◽  
Long Chain

Dipole moments of straight-chain aliphatic esters Ia-Ic and IIa-IIf were measured in benzene solution. The observed trends are poorly reproduced by the classical Smith-Eyring theory; the reason may be partly the unknown conformation, partly even donor-acceptor complexes with the solvent. No deviations were observed with the highest members of the series, attributable to violation of some basic assumptions of the theory of dielectrics.

scholarly journals Self-assembly of alkyl chains of fatty acids in papermaking systems: A review of related pitch issues, hydrophobic sizing, and pH effects

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 4591-4635
Author(s):  
Martin A. Hubbe ◽  
Douglas S. McLean ◽  
Karen R. Stack ◽  
Xiaomin Lu ◽  
Anders Strand ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Self Assembly ◽  
Review Article ◽  
Ph Effects ◽  
Monolayer Films ◽  
Alkyl Chains ◽  
Ph Values ◽  
Self Association ◽  
Long Chain

This review article considers the role of fatty acids and the mutual association of their long-chain (e.g. C18) alkyl and alkenyl groups in some important aspects of papermaking. In particular, published findings suggest that interactions involving fatty acids present as condensed monolayer films can play a controlling role in pitch deposition problems. Self-association among the tails of fatty acids and their soaps also helps to explain some puzzling aspects of hydrophobic sizing of paper. When fatty acids and their soaps are present as monolayers in papermaking systems, the pH values associated with their dissociation, i.e. their pKa values, tend to be strongly shifted. Mutual association also appears to favor non-equilibrium multilayer structures that are tacky and insoluble, possibly serving as a nucleus for deposition of wood extractives, such, as resins and triglyceride fats, in pulp and paper systems.

Excess heat capacities and excess volumes of tetraalkyltin compounds: . Effect of correlations of molecular orientations and steric hindrance. Part 1

1984 ◽  
Vol 62 (6) ◽  
pp. 1008-1015 ◽  
Author(s):  
Bernard Riedl ◽  
Geneviève Delmas
Keyword(s):  
Steric Hindrance ◽  
Central Atom ◽  
Orientational Order ◽  
Excess Volumes ◽  
Pure Liquid ◽  
Flory Theory ◽  
Flow Calorimeter ◽  
Alkyl Chains ◽  
Chain Compounds ◽  
Long Chain

A Picker flow calorimeter has been used to obtain molar excess capacities [Formula: see text] through the concentration range at 25 °C for the systems [Formula: see text] where R is the alkyl group CnH2n+1, (n = 1, 2, 3, 4, 8, 12). Excess volumes have also been measured for the mixtures. Two contributions to [Formula: see text] and vE were investigated: those associated with disordering the long alkyl chains and with steric hindrance. The steric hindrance contribution has been found to occur for molecules having a highly substituted central atom. The sign of this contribution is negative in hE and positive in [Formula: see text], indicative of an ordering or loss of mobility for the molecules going from pure liquid to solution. The [Formula: see text] results confirm the more sterically hindered character of the ethyl and propyl derivatives already found with hE. The separation of the disorder and steric contribution is possible in systems involving long-chain compounds. It is found that the orientational order contribution diminishes more slowly with temperature than the steric hindrance effect. The trend of vE in the series is reasonably well predicted by the Prigogine–Patterson–Flory theory.

Discotic Liquid Crystals of Transition metal Complexes 23: Synthesis and Mesomorphism of Tetrakis(3,4-di-n-alkylphenyl)porphyrin Derivatives and Their Metal Complexes

1999 ◽  
Vol 03 (04) ◽  
pp. 249-258 ◽  
Author(s):  
KAZUCHIKA OHTA ◽  
MASAHIRO ANDO ◽  
IWAO YAMAMOTO
Keyword(s):  
Liquid Crystal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Room Temperature ◽  
Discotic Liquid Crystals ◽  
X Ray ◽  
Alkyl Chains ◽  
Porphyrin Derivatives ◽  
Crystal Phases ◽  
Long Chain

Five novel long-chain-substituted porphyrin derivatives, tetrakis(3,4-dialkylphenyl)porphyrins (abbreviated as (Cn)8 TPPH 2 (n = 8, 12, 18), ( C 18)8 TPPCu and ( C 18)8 TPPNi ), were synthesized and their mesomorphism was investigated. It was found that the (Cn)8 TPPH 2 (n = 8, 12), derivatives are isotropic liquids at room temperature and that each of the ( C 18)8 TPPM ( M ≡ H 2, Cu , Ni ) derivatives has two liquid crystal phases M1 and M2 and two unidentified phases X1 and X2. It was revealed by X-ray studies that the M2 phase is a discotic lamellar (DL) phase. Interestingly, these porphyrin derivatives exhibit not a columnar but a lamellar mesophase, even though they have a disk-like central core with eight alkyl chains in the surroundings.

Synthesis of 6-hydroxy-N-(6-methylpyridin-2-yl) naphthalene-2- carboxamide and its alkoxy analogues

2017 ◽  
Vol 1 (3) ◽  
Author(s):  
Braja G. Bag ◽  
Subrata Ghorai ◽  
Saikat K. Panja ◽  
Shaishab K. Dinda ◽  
Koushik Paul
Keyword(s):  
Self Assembly ◽  
Alkyl Chains ◽  
Replication Studies ◽  
Naphthoic Acid ◽  
New Strategy ◽  
Donor Acceptor ◽  
High Yields ◽  
Self Replication

6-hydroxy-N-(6-methylpyridin-2-yl)naphthalene-2- carboxamide and its alkoxy analogues bearing long alkyl chains have been synthesized using 6-hydroxy-2-naphthoic acid and 2-amino-6-picoline. The facile synthetic scheme reported here using conventional laboratory reagents opens up a new strategy for the generation of libraries of such compounds in high yields. The H-bond donor acceptor groups along with the reactive 2-naphthol moiety present in the target compounds make them useful for their use in self-assembly and self-replication studies.

Quinacridone-pyridine dicarboxylic acid based donor–acceptor supramolecular nanobelts for significantly enhanced photocatalytic hydrogen production

2020 ◽  
Vol 8 (3) ◽  
pp. 930-934
Author(s):  
Mengyu Xu ◽  
Kangyi Kong ◽  
Haoran Ding ◽  
Yanmeng Chu ◽  
Shicong Zhang ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Dicarboxylic Acid ◽  
Photocatalytic Hydrogen Production ◽  
Alkyl Chains ◽  
Pyridine Dicarboxylic Acid ◽  
Donor Acceptor ◽  
Self Assembled

Self-assembled nanobelt photocatalysts with quinacridone containing different alkyl chains as donor and pyridine dicarboxylic acid as acceptor were firstly developed for H2 evolution. SQAP-C4 without cocatalyst of Pt exhibited HER of 656 μmol h−1 g−1.

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