scholarly journals Binding Properties of a Dinuclear Zinc(II) Salen-Type Molecular Tweezer with a Flexible Spacer in the Formation of Lewis Acid-Base Adducts with Diamines

Inorganics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 49
Author(s):  
Gabriella Munzi ◽  
Giuseppe Consiglio ◽  
Salvatore Failla ◽  
Santo Di Bella
Keyword(s):  
Lewis Acid ◽  
Degrees Of Freedom ◽  
Binding Constants ◽  
Molecular Structures ◽  
Acid Base ◽  
Binding Properties ◽  
Binding Characteristics ◽  
Fluorescence Studies ◽  
Flexible Spacer ◽  
Molecular Tweezer

In this paper we report the binding properties, by combined 1H NMR, optical absorption, and fluorescence studies, of a molecular tweezer composed of two Zn(salen)-type Schiff-base units connected by a flexible spacer, towards a series of ditopic diamines having a strong Lewis basicity, with different chain length and rigidity. Except for the 1,2-diaminoethane, in all other cases the formation of stable 1:1 Lewis acid-base adducts with large binding constants is demonstrated. For α,ω-aliphatic diamines, binding constants progressively increase with the increasing length of the alkyl chain, thanks to the flexible nature of the spacer and the parallel decreased conformational strain upon binding. Stable adducts are also found even for short diamines with rigid molecular structures. Given their preorganized structure, these latter species are not subjected to loss of degrees of freedom. The binding characteristics of the tweezer have been exploited for the colorimetric and fluorometric selective and sensitive detection of piperazine.

Diorganogallium β-Diketonates and Their Lewis Acid−Base Adducts. Crystal and Molecular Structures of Mes2Ga(hfac) and Me2Ga(hfac)·NC5H5

1998 ◽  
Vol 17 (6) ◽  
pp. 1101-1108 ◽  
Author(s):  
O. T. Beachley, ◽  
James R. Gardinier ◽  
Melvyn Rowen Churchill ◽  
Laurence M. Toomey
Keyword(s):  
Lewis Acid ◽  
Molecular Structures ◽  
Acid Base ◽  
Crystal And Molecular Structures

Donor-Acceptor Complexes between Organoamines and Phosphorus Tribromide

2001 ◽  
Vol 56 (11) ◽  
pp. 1163-1171 ◽  
Author(s):  
Gerhard Müller ◽  
Jörg Brand ◽  
Simone Elisabeth Jetter
Keyword(s):  
Lewis Acid ◽  
Phosphorus Atom ◽  
Chair Conformation ◽  
Molecular Structures ◽  
Ionic Character ◽  
Crystal Data ◽  
Acid Base ◽  
Crystal And Molecular Structures ◽  
Phosphorus Tribromide ◽  
Donor Acceptor

Lewis acid-base adducts between NMe3, tmeda (N ,N ,N′ ,N′-tetramethylethylenediamine), and 1.4-dimethylpiperazine as donors and PBr3 as acceptor have been prepared and structurally characterized. NMe3 and tmeda form 1:1 adducts (Me3N)PBr3 (1) and (tmeda)PBr3 (2), respectively, while 1,4-dimethylpiperazine adds 2 molecules of PBr3 leading to [(1,4-dimethylpiperazine)( PBr3)2] (3). Adduct 2 is found in two modifications 2a and 2b with different crystal and molecular structures. (Crystal data of 1: monoclinic P21/n, a = 5.983(3), b = 10.821(2), c = 13.877(5) Å, ß = 99.70(2)°, Z = 4. 2a: monoclinic P21/c, a = 7.891(1), b = 12.826(1), c = 12.218(2) Å ,ß = 102.162(6)°, Z = 4. 2b: monoclinic P21/n, a = 11.687(2), b = 8.375(1), c = 12.668(1) Å, ß = 102.74(1)°, Z = 4. 3: monoclinic P21/c, a = 6.383(3), b = 16.36(3), c = 8.407(3) Å , ß = 101.49(2)°, Z= 2). The molecular structures of 1 and 2 indicate a partially ionic character with a strongly bonded amine and one (1 ) or two (2 ) weakly bonded bromine atoms. In 2 the donor tmeda is bonded through both nitrogen atoms to one phosphorus atom. In 3 the 1,4-dimethylpiperazine ring is in chair conformation, the methyl and PBr3 substituents being in equatorial and axial positions, respectively. Due to axial-axial repulsion the N-P donor-acceptor bonds are long while the P-Br bonds are rather uniform in length.

Solvation and redox properties of [Co(en)3]3+-[Co(en)3]2+ system

1980 ◽  
Vol 45 (2) ◽  
pp. 335-338 ◽  
Author(s):  
Adéla Kotočová ◽  
Ulrich Mayer
Keyword(s):  
Hydrogen Bond ◽  
Lewis Acid ◽  
Specific Interaction ◽  
Redox Properties ◽  
Solvation Effect ◽  
Interacting Particles ◽  
Acid Base ◽  
Polar Solvents ◽  
Oxidation Reduction ◽  
Solvent Molecules

The solvation effect of a number of nonaqueous polar solvents was studied on the oxidation-reduction properties of the [Co(en)3]3+-[Co(en)3]2+ system. Interactions of these ions with the solvent molecules are discussed in terms of their coordination, which is accompanied by a specific interaction of the Lewis acid-base type, namely formation of a hydrogen bond between the interacting particles. This is the main controlling factor of the redox properties of the studied system.

Chalcogen versus Dative Bonding in [SF3]+ Lewis Acid–Base Adducts: [SF3(NCCH3)2]+, [SF3(NC5H5)2]+, and [SF3(phen)]+ (phen = 1,10-phenanthroline)

2021 ◽  
Vol 60 (6) ◽  
pp. 3893-3901
Author(s):  
Douglas Turnbull ◽  
Praveen Chaudhary ◽  
Paul Hazendonk ◽  
Stacey D. Wetmore ◽  
Michael Gerken
Keyword(s):  
Lewis Acid ◽  
Acid Base

scholarly journals Lewis acid / Base-free Strategy for the Synthesis of 2-Arylthio and Selenyl Benzothiazole / Thiazole and Imidazole

2021 ◽  
Vol 27 (1) ◽  
pp. 17-23
Author(s):  
Guniganti Balakishan ◽  
Gullapalli Kumaraswamy ◽  
Vykunthapu Narayanarao ◽  
Pagilla Shankaraiah
Keyword(s):  
Lewis Acid ◽  
Bond Formation ◽  
Acid Base ◽  
Mechanistic Pathway ◽  
Wide Range ◽  
Acid And Base ◽  
Lewis Acid And Base ◽  
Sulfur Bond

Abstract A Cu(II)-catalyzed Csp2-Se and Csp2-Sulfur bond formation was achieved with moderate to good yields without the aid of Lewis acid and base. The reaction is compatible with a wide range of heterocycles such as benzothiazole, thiazole, and imidazole. Also, this typical protocol is found to be active in thio-selenation via S-H activation. Additionally, we proposed a plausible mechanistic pathway involving Cu(III) putative intermediate.

scholarly journals Novel hydrogen chemisorption properties of amorphous ceramic compounds consisting of p-block elements: exploring Lewis acid-base Al–N pair site formed in-situ within polymer-derived silicon-aluminum-nitrogen-based system

2021 ◽  
Author(s):  
Shotaro Tada ◽  
Norifumi Asakuma ◽  
Shiori Ando ◽  
Toru Asaka ◽  
Yusuke Daiko ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Active Site ◽  
Hydrogen Chemisorption ◽  
Acid Base ◽  
Polymer Derived Ceramics ◽  
System P ◽  
Ceramic Compounds ◽  
The Relationship

This paper reports on the relationship between the H2 chemisorption properties and reversible structural reorientation of the possible active site around Al formed in-situ within polymer-derived ceramics (PDCs) based on...

Manipulation of Lewis acid–base complexation in the Zr-centered quaternary system for monodisperse spherical zircons

2020 ◽  
Author(s):  
Shan Peng ◽  
Zhongqiu Chen ◽  
Qing Huang ◽  
Xiaohong Xia ◽  
Zhuo Wang ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Quaternary System ◽  
Acid Base
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