scholarly journals Schiff base equilibria. III. N-Methylsalicylideneimine

1966 ◽  
Vol 19 (2) ◽  
pp. 229 ◽  
Author(s):  
RW Green ◽  
Mesurier EL Le
Keyword(s):  
Schiff Base ◽  
Formation Constant ◽  
Distribution Coefficients ◽  
Neutral Form ◽  
Methyl Amine ◽  
Phenolic Group

At 25� the formation constant of the Schiff base of salicylaldehyde and methyl- amine is 3.72 x 104; and the pK of the phenolic group of the Schiff base is 11.7. The neutral form of the imine has distribution coefficients of 23.5 between water and toluene and 9.0 between water and cyclohexane.

Schiff base equilibria. I. Formation and distribution of N-n-butylsalicylideneimine

1965 ◽  
Vol 18 (3) ◽  
pp. 329 ◽  
Author(s):  
RW Green ◽  
PW Alexander
Keyword(s):  
Aqueous Solution ◽  
Schiff Base ◽  
Distribution Coefficient ◽  
Equilibrium Constant ◽  
Neutral Form ◽  
Phenolic Group

The equilibrium constant governing the formation of a Schiff base from salicylaldehyde and n-butylamine in aqueous solution has been evaluated by spectrophotometry as 5.62 x 104. The pK of the phenolic group of the Schiff base is 12.0. These constants have been used to account for the distribution of salicylaldehyde between water and toluene in the presence of butylamine. The neutral form of the Schiff base has a distribution coefficient of 1.9 x 103.

Schiff base equilibria. VI. n- and t-Butylimines of pyridine-2-aldehyde

1968 ◽  
Vol 21 (10) ◽  
pp. 2427 ◽  
Author(s):  
RW Green ◽  
MJ Rogerson
Keyword(s):  
Schiff Base ◽  
Schiff Bases ◽  
Formation Constant ◽  
Equilibrium Constants

Equilibrium constants at 25� have been measured for the formation of Schiff bases of pyridine-2-aldehyde with n-butylamine (1.45 x 108) and t-butylamine (93). The Schiff base of salicylaldehyde with t-butylamine has a formation constant 9.1 x 108 and pK 13.0.

Schiff base equilibria. V. Beryllium complexes of N-ethylsalicylideneimine

1966 ◽  
Vol 19 (11) ◽  
pp. 2101 ◽  
Author(s):  
RW Green ◽  
RJ Sleet
Keyword(s):  
Schiff Base ◽  
Distribution Coefficient ◽  
Stability Constants ◽  
Formation Constant ◽  
Mixed Complex ◽  
High Ph ◽  
The Stability ◽  
Hydrolysis Of ◽  
Beryllium Complexes

The formation constant and pK at 25� of the Schiff base N- ethylsalicylideneimine (HL) have been found by spectrophotometry to be 2.75x104 and 11.8 respectively. The distribution coefficient of the base from water into toluene is 160. The stability constants of the beryllium complexes determined by solvent distribution are logβ1 10.4 and log β2 18.3, and the distribution coefficient of BeL2 is 260. At high pH the equilibria are complicated by hydrolysis of the Be2+ ion and by formation of the mixed complex, BeL(OH)-2. The latter is formed according to the reaction BeL(H2O)+2 ↔ BeL(OH)-2+2H+ with logKm2 -18.4.

scholarly journals Schiff base equilibria. VII. Formation and distribution of N-(β-Hydroxyethyl)salicylideneimine

1969 ◽  
Vol 22 (5) ◽  
pp. 917 ◽  
Author(s):  
RW Green ◽  
RJ Sleet
Keyword(s):  
Aqueous Solution ◽  
Schiff Base ◽  
Formation Constant ◽  
Equilibrium Constants

The formation constant and pK of the Schiff base N-(8- hydroxyethyl)salicylideneimine in aqueous solution at 25� have been determined spectrophotometrically to be 5.01 x 103 and 11.4 respectively. These equilibrium constants have been used to account for the distribution of the imine between water and chloroform.

scholarly journals A Ternary Nickel(II) Schiff Base Complex Containing Di-anionic and Neutral Forms of a Dithiocarbazate Schiff Base

Molbank ◽  
10.3390/m1057 ◽  
2019 ◽  
Vol 2019 (2) ◽  
pp. M1057 ◽  
Author(s):  
Yusof ◽  
Nasri ◽  
Ravoof ◽  
Tiekink
Keyword(s):  
Hydrogen Bond ◽  
Schiff Base ◽  
Three Dimensional ◽  
Schiff Base Complex ◽  
Planar Geometry ◽  
Neutral Form ◽  
X Ray ◽  
Niii Complex ◽  
Square Planar ◽  
Supramolecular Chains

The title NiII complex, Ni(L)(LH2) (1), where LH2 is S-2-methybenzyl-β-N-(2-hydroxy-3-methoxybenzylmethylene) dithiocarbazate, was isolated from the reaction of Ni(acetate)2·4H2O and two molar equivalents of LH2. The complex was characterized by elemental analysis, spectroscopy (IR and UV) as well as by a single-crystal X-ray structure determination. The nickel(II) center is coordinated within a cis-NOS2 donor set that defines a square planar geometry. Three donor atoms, i.e., N, O, and S, are provided by a doubly deprotonated S-2-methybenzyl-β-N-(2-hydroxy-3-methoxybenzylmethylene) dithiocarbazate ligand while the fourth donor, i.e., a thione-S, comes from the neutral form of the dithiocarbazate ligand. In the LH2 ligand, an intramolecular hydroxy-O-H…N(imine) hydrogen bond is found. There is also an intra-ligand, charge assisted amine-N-H…O(phenoxide) hydrogen bond. A notable feature of the molecular packing is the formation of supramolecular chains sustained by π…π stacking interactions whereby the interacting rings are the five- and six-membered chelate and methoxybenzene rings. The chains are connected into a three-dimensional architecture by methyl-C-H…O(methoxy), methoxy-C-H…S(ester), and tolyl-C-H…π(tolyl) interactions.

Spin-crossover in an iron(iii) complex showing a broad thermal hysteresis

2021 ◽  
Author(s):  
Cyril Rajnák ◽  
Romana Mičová ◽  
Ján Moncoľ ◽  
Ľubor Dlháň ◽  
Christoph Krüger ◽  
...  
Keyword(s):  
Schiff Base ◽  
Schiff Base Ligand ◽  
Spin Crossover ◽  
Thermal Hysteresis ◽  
Mononuclear Complex ◽  
Hysteresis Width ◽  
Thermally Induced

A pentadentate Schiff-base ligand 3,5Cl-L2− and NCSe− form a iron(iii) mononuclear complex [Fe(3,5Cl-L)(NCSe)], which shows a thermally induced spin crossover with a broad hysteresis width of 24 K between 123 K (warming) and 99 K (cooling).

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