THE PREPARATION OF SOME THIOSEMICARBAZONES AND THEIR COPPER COMPLEXES

1961 ◽  
Vol 39 (5) ◽  
pp. 973-985 ◽  
Author(s):  
B. A. Gingras ◽  
R. L. Somorjai ◽  
C. H. Bayley
Keyword(s):  
Hydrogen Atom ◽  
Nitrogen Atom ◽  
Infrared Spectra ◽  
Copper Complexes ◽  
Medium Band

Reactions of N- and S-substituted thiosemicarbazones with Cu(I) have been examined. No complexes are formed when the S atom is substituted and(or) when the N2 hydrogen atom is replaced by Me. 4,4-Dimethyl derivatives not only give the usual 1:1 complexes, but also 2:1 complexes (2 thiosemicarbazones to 1 copper) in which copper has been oxidized to Cu(II). Reactions of thiosemicarbazones with Cu(II) give 1:1, 2:1, and probably a mixture which corresponds to 2:3 complexes. A discussion on the possible structures for the 1:1 complexes is given and they are best represented as polymers, the metal being bonded to the sulphur and to a nitrogen atom of the thioseraicarbazide portion of the molecule. Infrared spectra of these compounds have been examined, particularly in the 1100 cm−1 region where a strong to medium band disappears in going from thiosemicarbazones to copper complexes. It is suggested that this band is due to the C=S vibration.

THE PREPARATION OF SOME THIOSEMICARBAZONES AND THEIR COPPER COMPLEXES: PART III

1962 ◽  
Vol 40 (6) ◽  
pp. 1053-1059 ◽  
Author(s):  
B. A. Gingras ◽  
T. Suprunchuk ◽  
C. H. Bayley
Keyword(s):  
Hydrogen Atom ◽  
Complex Formation ◽  
Infrared Spectra ◽  
Copper Complexes ◽  
Cyclization Product

Reactions of some diketones with thiosemicarbazide have been studied under various conditions. Monothiosemicarbazones, dithiosemicarbazones, and cyclization products can be obtained. It was found that dithiosemicarbazones form 1:1 complexes with Cu(II) but failed to react with Cu(I). Dithiosemicarbazones in which the N2-hydrogen atom has been replaced by Me do not form complexes, confirming our views about the importance of this hydrogen atom in the thione ↔ thiol tautomerism necessary for complex formation. 4,4-Dimethyldithiosemicarbazones behave like the unsubstituted parent compounds in forming 1:1 complexes with Cu(II). Infrared spectra provide evidence for the structure of a cyclization product, 5,6-diphenyl-3-thio-1,2,4-triazine, which had been erroneously described by various authors as the thiol tautomer, 5,6-diphenyl-3-mercapto-1,2,4-triazine.

Infrared spectra of the interactions of aniline and porous glass surfaces

1969 ◽  
Vol 47 (8) ◽  
pp. 1281-1287 ◽  
Author(s):  
M. J. D. Low ◽  
V. V. Subba Rao
Keyword(s):  
Nitrogen Atom ◽  
Aromatic Ring ◽  
Secondary Amine ◽  
Infrared Spectra ◽  
Porous Glass ◽  
Weak Interactions ◽  
Amine Group ◽  
Oh Groups ◽  
Glass Surfaces ◽  
Adsorption And Dissociation

Infrared spectra were recorded of aniline sorbed on highly dehydroxylated, deuterated, and on fluoridated porous glass as well as on pure and boria-impregnated silica. The results suggest that two types of weak interactions involving the surface SiOH and B—OH groups occurred; the nitrogen atom of the amine was hydrogen bonded to surface OH and there was an interaction between OH groups and the π system of the aromatic ring. Some aniline chemisorbed on surface boron via the nitrogen atom of the amine group. Some aniline chemisorbed dissociatively to form secondary amine structures bonded through the nitrogen to surface boron atoms and new B—OH groups formed. Surface boron impurity acted as an adsorption and dissociation center.

The infrared spectra of theobromine salts

1967 ◽  
Vol 45 (23) ◽  
pp. 2899-2902 ◽  
Author(s):  
Denys Cook ◽  
Zephyr R. Regnier
Keyword(s):  
Hydrogen Bond ◽  
Nitrogen Atom ◽  
Infrared Spectra ◽  
Imidazole Ring ◽  
Free Base ◽  
Absorption Bands ◽  
Out Of Plane ◽  
Stretching Vibrations ◽  
Deformation Modes ◽  
Infrared Absorption Bands

From the infrared spectra of theobromine salts it is concluded that the salts are probably arranged in hydrogen-bonded centrosymmetric pairs involving [Formula: see text] interactions. [Formula: see text] anion− hydrogen bonds are formed by protonation of the free nitrogen atom (N9) in the imidazole ring. Infrared absorption bands arising from the former hydrogen bond constantly appear near 3 000 cm−1, whereas those from the latter shift from 2 580 to 3 300 cm−1, depending on the anion. In-plane NH and N+H deformation modes give bands near 1 485 and 1 160 cm−1, respectively. Out-of-plane NH modes have been located, but precise assignments are not possible.The assignments for some other bands which show deuteration shifts are detailed, and the carbonyl stretching vibrations which increase in frequency on protonation of the free base are identified.

THE PREPARATION OF SOME THIOSEMICARBAZONES AND THEIR COPPER COMPLEXES. PART I

1960 ◽  
Vol 38 (5) ◽  
pp. 712-719 ◽  
Author(s):  
B. A. Gingras ◽  
R. W. Hornal ◽  
C. H. Bayley
Keyword(s):  
Complex Formation ◽  
Aromatic Aldehyde ◽  
Infrared Spectra ◽  
Copper Complexes ◽  
Chemical Evidence

A number of thiosemicarbazones and their 1:1 copper complexes are described and the possible structures of the latter are discussed. Formation of copper complexes from aromatic aldehyde and ketone thiosemicarbazones results in a loss of one H atom as indicated by infrared spectra. In the aliphatic series, no loss of H atom is apparent upon complex formation. It is reasonable to assume that different processes are involved resulting in two possible structures for the aromatic and the aliphatic copper complexes. Some chemical evidence supports this view.

Kinetics of acid-catalyzed cyclization of substituted hydantoinamides to substituted hydantoins

1987 ◽  
Vol 52 (8) ◽  
pp. 1999-2004 ◽  
Author(s):  
Jaromír Kaválek ◽  
Vladimír Macháček ◽  
Gabriela Svobodová ◽  
Vojeslav Štěrba
Keyword(s):  
Hydrogen Atom ◽  
Nitrogen Atom ◽  
Hydrochloric Acid ◽  
Dissociation Constants ◽  
Amide Group ◽  
The Other ◽  
Methyl Group ◽  
Acid Catalyzed ◽  
Cyclization Rate ◽  
Kinetics Of

The kinetics of acid-catalyzed cyclization of the hydantoinamides type R3-N(5)H-CO-N(3)R2-CH2-CO-N(1)HR1 (R1, R2, R3 = H and/or CH3) has been studied in 0·5 to 5 mol l-1 hydrochloric acid. The cyclization rate is limited by the rate of the attack of nitrogen atom N(5) on the carbon atom of the protonated amide group. The dissociation constants of the protonated hydantoinamides and rate constants of their cyclizations have been determined. Replacement of hydrogen atom by methyl group at the N(5) nitrogen atom accelerates the cyclization about two times., the same substitution at N(3) accelerates about 50x, whereas at N(1) it results in a 300 fold retardation. With the hydantoinamides having R3 = CH3, the cyclization rate of the protonated hydantoinamide increases with increasing concentration of hydrochloric acid, whereas with the other derivatives this value is independent of the acid concentration.

Sulphur-nitrogen chelating agents. VI. Five- and six-coordinate complexes of 3d metal ions with an SNN tridentate ligand

1969 ◽  
Vol 22 (8) ◽  
pp. 1613 ◽  
Author(s):  
PSK Chia ◽  
SE Livinhstone
Keyword(s):  
Metal Ions ◽  
High Spin ◽  
Infrared Spectra ◽  
Magnetic Moment ◽  
Nickel Complex ◽  
Copper Complexes ◽  
Chelating Agents ◽  
Iron Complex ◽  
Tridentate Ligand ◽  
Infrared Data

Mono-ligand complexes of 6-methylpyrid-2-yl-N-(2?-methylthiophenyl)- methyleneimine (SNSMe) of the type MX2(SNNMe) (M = Mn, Fe, Co, Xi, and Cu; X = Cl, Br, I, or NCS) have been prepared. Infrared data show that in all the complexes the ligand (SNNMe) is tridentate. The electronic and infrared spectra indicate that the complexes of manganese, iron, and cobalt are five-coordinate, whereas the nickel and copper complexes are six-coordinate and polymeric. The complex CO(NO3)2(SNNMe) is six- coordinate and contains one bidentate and one unidentate nitrato group. ��� The bis-ligand complexes [N(SNNMe)2]Y2 (M = Fe, Ni, and Cu; Y = ClO4 or BF4) were also isolated. The iron complex is low-spin (μ 1.5 B.M.) but the magnetic moment of the nickel complex (μ 3.0 B.M.) is normal for high-spin octahedral nickel(II).

scholarly journals Cationic DABCO-based Catalyst for Site-Selective C−H Alkylation via Photoinduced Hydrogen-Atom Transfer

2021 ◽  
Author(s):  
Akira Matsumoto ◽  
Keiji Maruoka
Keyword(s):  
Hydrogen Atom ◽  
Nitrogen Atom ◽  
Crucial Role ◽  
Active Species ◽  
Hydrogen Atom Transfer ◽  
Atom Transfer ◽  
Mechanistic Studies ◽  
Complex Molecules ◽  
Site Selectivity ◽  
Site Selective

A novel class of hydrogen-atom transfer (HAT) catalysts based on the readily available and tunable 1,4-diazabicyclo[2.2.2]octane (DABCO) structure was designed, and their photoinduced HAT catalysis ability was demonstrated. The combination of the optimal HAT catalyst with an acridinium-based organophotoredox catalyst enables highly efficient and site-selective C−H alkylation of substrates ranging from unactivated hydrocarbons to complex molecules. Notably, a HAT catalyst with additional substituents adjacent to a nitrogen atom further improved the site-selectivity. Mechanistic studies suggested that the N-substituent of the catalyst plays a crucial role, assisting in the generation of a dicationic aminium radical as an active species for the HAT process.

The infrared spectra of caffeine salts

1967 ◽  
Vol 45 (23) ◽  
pp. 2895-2897 ◽  
Author(s):  
Denys Cook ◽  
Zephyr R. Regnier
Keyword(s):  
Nitrogen Atom ◽  
Infrared Spectra ◽  
Imidazole Ring ◽  
Out Of Plane ◽  
Plane Bending ◽  
Bending Modes

The infrared spectra of caffeine and its salts show that protonation occurs at position 9, the free nitrogen atom in the imidazole ring. N+H stretching and in-plane and out-of-plane bending modes have been assigned with the help of the deuterated salts. Protonation causes changes in some ring modes, accompanied by shifts in the carbonyl stretching frequencies to higher values.

Some studies in inorganic complexes. XX. Further reactions of 2-thioaminopyridine

1966 ◽  
Vol 19 (11) ◽  
pp. 2059 ◽  
Author(s):  
GJ Sutton
Keyword(s):  
Magnetic Susceptibility ◽  
Nitrogen Atom ◽  
Absorption Spectra ◽  
Infrared Spectra ◽  
Visible Region ◽  
Metal Chelates ◽  
Sulphur Atom ◽  
Inorganic Complexes

The following complexes of 2-thioamidopyridine (thiopic) were prepared and studied : [RhCl2 thiopic2]Cl,2H2O; [RhCl2 thiopic2][RhCl4 thiopic]; [RhCl, thiopic2]ClO4; [RhBr2 thiopic2]ClO4; [RhI2 thiopic2]ClO4,H2O; [Rh thiopic3][ClO4]3; [Ag thiopic]ClO4; [AuCl2 thiopic][AuCl4]; [Au thiopic2][AuI2]; [RuCl2 thiopic2], C2H5OH; [Os thiopic3]Br3; [Cr thiopic3]Br3; [MnI3 thiopic2]; [In thiopic3]Cl3,H2O. The following substances were also prepared and studied: [RhI2 pic2]I2,H2O; [RhCl, en,]Cl,H2O; [Rh phenan3]Br3 (where pic is 2-aminomethylpyridine, en is ethylenediamine, and phenan is 1,10-phenanthroline). The conductances of all of the aforementioned substances in NN?-dimethylformamide agreed with their structures as metal chelates as indicated. Studies of absorption spectra in the visible region were also made, and infrared spectra showed that bonding had occurred through the sulphur atom of the -C(=S)NH, group in the case of rhodium(III), gold(I), gold(III), ruthenium(II), osmium(III), and silver(I) complexes, whereas with chromium(III), manganese(II), and indium(III) coordination was by the nitrogen atom. Measurements of magnetic susceptibility showed that the rhodium(III), gold(I), gold(III), ruthenium(II), and osmium(III) complexes were spin-paired, whereas those of chromium(III) and manganese(II) were spin free.

Sign in / Sign up

Export Citation Format

Share Document