scholarly journals The Coordination Chemistry of Some Sulphur-Nitrogen Ligands

2021 ◽  
Author(s):  
◽  
Allen Lee Galyer
Keyword(s):  
Coordination Chemistry ◽  
Electronic Spectra ◽  
Thiol Groups ◽  
Amino Groups ◽  
Nitrogen Ligands ◽  
Tetradentate Ligands ◽  
Nitrogen Donor

<p>Some nickel(II) and copper(II) complexes of 2-(benzylthio)ethylamine have been isolated and characterised with respect to infrared and electronic spectra. With nickel(II) only the bis salts were obtained and they were all paramagnetic. An investigation of the nickel(II) and copper(II) complexes of three tetradentate ligands, each containing two sulphur and two nitrogen donor atoms, has been made. One of these, 1,9-diamino 3,7-dithianonane has been compared to the nitrogen analogue, 1,9-diamino 3,7-diazanonane. Attempts to bridge and cyclise complexes using reactions of acetone with coordinated amino groups and halides with coordinated thiol groups are also reported. Finally a novel S-detritylation reaction is discussed.</p>

scholarly journals The Coordination Chemistry of Some Sulphur-Nitrogen Ligands

2021 ◽  
Author(s):  
◽  
Allen Lee Galyer
Keyword(s):  
Coordination Chemistry ◽  
Electronic Spectra ◽  
Thiol Groups ◽  
Amino Groups ◽  
Nitrogen Ligands ◽  
Tetradentate Ligands ◽  
Nitrogen Donor

<p>Some nickel(II) and copper(II) complexes of 2-(benzylthio)ethylamine have been isolated and characterised with respect to infrared and electronic spectra. With nickel(II) only the bis salts were obtained and they were all paramagnetic. An investigation of the nickel(II) and copper(II) complexes of three tetradentate ligands, each containing two sulphur and two nitrogen donor atoms, has been made. One of these, 1,9-diamino 3,7-dithianonane has been compared to the nitrogen analogue, 1,9-diamino 3,7-diazanonane. Attempts to bridge and cyclise complexes using reactions of acetone with coordinated amino groups and halides with coordinated thiol groups are also reported. Finally a novel S-detritylation reaction is discussed.</p>

Reaction of Fluorescein Isothiocyanate with Thiol and Amino Groups of Sarcoplasmic ATPase

1985 ◽  
Vol 40 (11-12) ◽  
pp. 863-875 ◽  
Author(s):  
Gertrude Swoboda ◽  
Wilhelm Hasselbach
Keyword(s):  
Absorption Maximum ◽  
Sodium Dodecylsulfate ◽  
Specific Effect ◽  
Fluorescein Isothiocyanate ◽  
Thiol Groups ◽  
Amino Groups ◽  
Model Compounds ◽  
Intramolecular Transfer ◽  
Dodecyl Ether ◽  
Lysyl Residue

Abstract Several model compounds containing thiol and/or amino groups (mercaptoethanol, glutathione, cysteine, ethanolamine, glycine) were studied with respect to their reactivity towards fluorescein isothiocyanate (followed spectrophotometrically at 504 and 412 nm), stability of product and long­ wave absorption maximum of the fluorescein residue attached. Thiol groups reacted by far more readily than amino groups. A specific effect was observed with cysteine, indicating an intramolecular transfer of the fluorescein residue from SH to NH2.With sarcoplasmic vesicles both types of reactions were observed. The ratio of products, which can be distinguished by their different stabilities and absorption spectra, depended on the absence or presence of detergents. While with native vesicles the NH2 reaction predominated, with vesicles solubilized with sodium dodecylsulfate, octaethyleneglycol mono-n-dodecyl ether or 1-0-tetradecyl-propanediol-(1,3)-3-phosphorylcholine the SH reaction became prevailing. Already 0.35 mg sodium dodecylsulfate per mg protein were sufficient to give rise to dithiourethane formation exclusively. Excess fluorescein isothiocyanate reacted with several thiol groups of dodecylsulfate-solubilized vesicles. In the presence of ATP binding of fluorescein isothiocyanate to native vesicles was significantly reduced.Total blockage of the vesicular SH groups with N-ethyl-maleimide led to preparations that reacted with fluorescein isothiocyanate much more slowly, compared to native vesicles. Octaethy­ leneglycol mono-n-dodecyl ether or 1-0-tetradecyl-propanediol-(1,3)-3-phosphorylcholine in the assay accelerated the thioureide formation from N-ethylmaleimide modified vesicles, whereas sodium dodecylsulfate prevented it almost completely.Our results support the suggestion that one or several thiol groups in vicinity of the highly reactive lysyl residue might play a role in the fast specific reaction, which is only observed with intact native vesicles.

Organoamido- and Aryloxo-lanthanoids. XII. The Coordination Chemistry of Bis(2-phenylindol-1-yl)ytterbium(II), and the X-Ray Crystal Structures of Yb(pin)2(diglyme)(thf) and [Yb(pin)2(dme)]2 (pin = 2-Phenylindol-1-yl, diglyme = Bis(2-methoxyethyl) Ether, thf Equals Tetrahydrofuran, dme = 1,2-Dimethoxyethane)

1995 ◽  
Vol 48 (12) ◽  
pp. 1933 ◽  
Author(s):  
CT Abrahams ◽  
GB Deacon ◽  
CM Forsyth ◽  
WC Patalinghug ◽  
BW Skelton ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Coordination Chemistry ◽  
Crystal Structures ◽  
Coordination Polyhedron ◽  
Basal Plane ◽  
Monoclinic Space Group ◽  
Coordinate Structure ◽  
Space Group ◽  
X Ray ◽  
Nitrogen Donor

With the facile displacement being utilized of thf from Yb(pin)2(thf)4 (pin = 2-phenylindol-1-yl, thf = tetrahydrofuran) in toluene solution, the complexes Yb(pin)2(dme)2 (dme = 1,2- dimethoxyethane), Yb(pin)2 (tmen)(tmen = N,N,N′,N′-tetramethylethane-1,2-diamine) and Yb(pin)2(diglyme)(thf) (diglyme = bis(2-methoxyethyl) ether) have been prepared from the respective ligands and Yb(pin)2(thf)4. Yb(pin)2 (diglyme) (thf) [monoclinic, space group P 21 /c, a 15.35(1), b 16.179(5), c 14.45(2) Ǻ, β 107.51(8)°, Z 4, R 0.044 for 2956 (I > 3σ(I)) 'observed' reflections] has a monomeric six-coordinate structure with transoid nitrogen donor atoms, N-Yb-N 143.6(4)° and an irregular coordination polyhedron described as either a distorted trigonal prism or a monocapped square pyramid. Attempted crystallization of Yb(pin)2 (thf) by partial desolvation of Yb(pin)2(thf)4 in hot toluene, containing a trace of dme, gave a mixture of red Yb(pin)2(thf) and orange [Yb(pin)2(dme)]2. The latter was independently synthesized by partial desolvation of Yb(pin)2(dme)2 in toluene. An X-ray crystal structure showed [Yb(pin)2(dme)]2 [monoclinic, space group P 21/c, a 11 .614(2), b 15.945(7), c 15.327(4) Ǻ, β 110.19(2)°, Z 2 dimers, R 0.070 for 2314 (I ≥ 3σ(I)) 'observed' reflections] to be a dimer with two bridging pin ligands, coordinated through nitrogen only. There is an approximately square pyramidal five-coordinate ytterbium environment with an apical dme oxygen, and with two bridging nitrogens, a terminal nitrogen, and a dme oxygen in the basal plane.

pKa-Werte von Ethidiumbromid und 7-Amino-9-phenyl-10- äthyl-phenanthridinium-bromid / pKa-Values of Ethidiumbromide and 7-Amino-9-phenyl-10-ethyl-phenanthridinium- bromide

1976 ◽  
Vol 31 (11-12) ◽  
pp. 656-660 ◽  
Author(s):  
Ingfried Zimmermann ◽  
Herbert Zimmermann
Keyword(s):  
Electronic Spectra ◽  
Water Solution ◽  
Ph Dependence ◽  
Quantum Mechanical ◽  
Amino Group ◽  
Quantum Mechanical Calculations ◽  
Acidic Water ◽  
Amino Groups ◽  
Electronic Density ◽  
Decreasing Ph

Abstract Ethidiumbromide (1) has two amino groups in 2-and 7-position which are protonated in acidic water solution. Both pKa-values of 1 are determined at 20 °C by means of the pH-dependence of the electronic spectra using a iterative calculating procedure, pKa1 = 0.713, pKa2 = 2.43. Acetylation of 1 and quantum mechanical calculations lead to the conclusion that the electronic density at the 7-amino group is greater than in 2-position. Therefore with decreasing pH preferably the 7-amino group is protonated (pKa2). followed by the protonation of the 2-amino group (pKa1). The pKa of 7-amino-9-phenyl-10-ethyl-phenanthridinium-bromide in water solution at 20 °C is determined to pKa= 1 .2 5 .

scholarly journals The reaction of aldolase with 2-methylmaleic anhydride

1970 ◽  
Vol 116 (5) ◽  
pp. 843-849 ◽  
Author(s):  
I. Gibbons ◽  
R. N. Perham
Keyword(s):  
Enzyme Activity ◽  
Maleic Anhydride ◽  
Enzymic Activity ◽  
Side Reactions ◽  
Rabbit Muscle ◽  
Thiol Groups ◽  
Amino Groups ◽  
Partial Loss ◽  
Reaction Proceeds ◽  
Citraconic Anhydride

1. The reaction of rabbit muscle aldolase with 2-methylmaleic anhydride is described. All the protein amino groups can be reversibly blocked. 2. As the reaction proceeds, the enzyme activity decreases until, at about 50% citraconylation of amino groups, the enzyme is completely inhibited. At this stage, little or no dissociation of the enzyme tetramer is observed and 75% of the activity is recoverable on unblocking the amino groups. 3. At 80% blocking, the enzyme is completely dissociated but little enzymic activity is recoverable after unblocking. Inability to recover activity after citraconylation and unblocking correlates with the onset of dissociation of the citraconyl-aldolase seen on ultracentrifugation. 4. The only irreversible modification of the enzyme primary structure detectable after the citraconylation and unblocking reactions is the partial loss of thiol groups. It is probable that this is responsible for the inability to reform active enzyme from the citraconylated subunit. 5. Other reversible side reactions of maleic anhydride and citraconic anhydride that may occur with proteins are discussed.

Strongly Phosphorescent Palladium(II) Complexes of Tetradentate Ligands with Mixed Oxygen, Carbon, and Nitrogen Donor Atoms: Photophysics, Photochemistry, and Applications

2013 ◽  
Vol 52 (45) ◽  
pp. 11775-11779 ◽  
Author(s):  
Pui Keong Chow ◽  
Chensheng Ma ◽  
Wai-Pong To ◽  
Glenna So Ming Tong ◽  
Shiu-Lun Lai ◽  
...  
Keyword(s):  
Carbon And Nitrogen ◽  
Tetradentate Ligands ◽  
Nitrogen Donor
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