scholarly journals Synthesis of stable polymetalated aromatic complexes through metal–macrocycle capsule-triggered cyclization

2018 ◽  
Vol 9 (6) ◽  
pp. 1481-1487 ◽  
Author(s):  
Xin He ◽  
Yang Xue ◽  
Cui-Cui Li ◽  
Yuechao Wang ◽  
Hong Jiang ◽  
...  
Keyword(s):  
Macrocyclic Ligand ◽  
Cyclization Reactions ◽  
Dynamic Coordination ◽  
Aromatic Complexes ◽  
Molecular Folding

A dynamic coordination capsule derived from coordination-driven molecular folding of a flexible macrocyclic ligand was applied to trigger cyclization reactions and encapsulate unprecedented polysilver complexes of four different heteroaromatics.

The Chemistry of Macrocyclic Ligand Complexes

1989 ◽  
Author(s):  
L. F. Lindoy
Keyword(s):  
Macrocyclic Ligand

Mechanistic Study and Development of Catalytic Reactions of Sm(II)

2018 ◽  
Author(s):  
Sandepan Maity ◽  
Robert Flowers
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Proton Donor ◽  
Catalytic Reactions ◽  
Mechanistic Study ◽  
Mechanistic Studies ◽  
Cyclization Reactions ◽  
Mechanistic Approach ◽  
Donor Source

Despite the broad utility and application of SmI<sub>2</sub>in synthesis, the reagent is used in stoichiometric amounts and has a high molecular weight, resulting in a large amount of material being used for reactions requiring one or more equivalents of electrons. We report mechanistic studies on catalytic reactions of Sm(II) employing a terminal magnesium reductant and trimethyl silyl chloride in concert with a non-coordinating proton donor source. Reactions using this approach permitted reductions with as little as 1 mol% Sm. The mechanistic approach enabled catalysis employing HMPA as a ligand, facilitating the development of catalytic Sm(II) 5-<i>exo</i>-<i>trig </i>ketyl olefin cyclization reactions.

Dynamic Coordination and Intervention Policy

2016 ◽  
Author(s):  
Lin William Cong ◽  
Steven R. Grenadier ◽  
Yunzhi Hu
Keyword(s):  
Dynamic Coordination ◽  
Intervention Policy

Azaoxa Macrocyclic and Acyclic Complexesof Lanthanides

1998 ◽  
Vol 63 (3) ◽  
pp. 363-370 ◽  
Author(s):  
Violetta Patroniak-Krzyminiewska ◽  
Wanda Radecka-Paryzek
Keyword(s):  
Schiff Base ◽  
Spectral Data ◽  
Macrocyclic Ligand ◽  
Lanthanide Ions ◽  
H Nmr ◽  
Elemental Analyses ◽  
Acyclic Complexes ◽  
Schiff Base Cyclocondensation

The template reactions of 2,6-diacetylpyridine with 3,6-dioxaoctane-1,8-diamine in the presence of dysprosium(III), thulium(III) and lutetium(III) chlorides and erbium(III) perchlorate produce the complexes of 15-membered macrocyclic ligand with an N3O2 set of donor atoms as a result of the [1+1] Schiff base cyclocondensation. In contrast, analogous reactions involving the lighter lanthanide ions (lanthanum(III), samarium(III) and europium(III)) yield the acyclic complexes with terminal acetylpyridyl groupings as products of the partial [2+1] condensation. The complexes were characterized by spectral data (IR, UV-VIS, 1H NMR, MS), and thermogravimetric and elemental analyses.

Anion effect on alkali ion-crown complex formation in a moderately concentrated solutions: A sensitive probe of hidden interionic interactions operating in dissociating protic solvents

1990 ◽  
Vol 55 (5) ◽  
pp. 1149-1161
Author(s):  
Jiří Závada ◽  
Václav Pechanec ◽  
Oldřich Kocián
Keyword(s):  
Hydrogen Bond ◽  
Complex Formation ◽  
Charge Density ◽  
Macrocyclic Ligand ◽  
Simple Explanation ◽  
Anion Effect ◽  
Protic Solvents ◽  
The Individual ◽  
Alkali Salts ◽  
Alkali Ion

A powerful anion effect destabilizing alkali ion-crown complex formation has been found to operate in moderately concentrated protic (H2O, CH3OH, C2H5OH) solution, following the order HO- > AcO- > Cl- > Br- > NO3- > I- > NCS-. Evidence is provided that the observed effect does not originate from ion-pairing. A simple explanation is provided in terms of concordant hydrogen bond bridges of exalted stability between the gegenions, M+···OR-H···(OR-H)n···OR-H···A-. It is proposed that encapsulation of alkali ion by the macrocyclic ligand leads to a dissipation of the cation charge density destroying its ability to participate in the hydrogen bond bridge. An opposition against the alkali ion-crown complex formation arises accordingly in the solution in dependence on strength of the hydrogen bridge; for a given cation, the hydrogen bond strength increases with increasing anion charge density from NCS- to HO-(RO-). It is pointed out, at the same time, that the observed anion effect does not correlate with the known values of activity coefficients of the individual alkali salts which are almost insensitive to anion variation under the investigated conditions. As a resolution of the apparent paradoxon it is proposed that, in absence of the macrocyclic ligand, the stabilizing (concordant) bonding between the gegenions is nearly balanced by a destabilizing (discordant) hydrogen bonding between the ions of same charge (co-ions). Intrinsic differences among the individual salts are thus submerged in protic solvents and become apparent only when the concordant bonding is suppressed in the alkali ion-crown complex formation.

A New Host Lattice Built of the Werner-Type Copper(I,II) Cyanide Complex Involving a Macrocyclic Ligand

1998 ◽  
Vol 63 (5) ◽  
pp. 622-627 ◽  
Author(s):  
Hidetaka Yuge ◽  
Takayoshi Soma ◽  
Takeshi Ken Miyamoto
Keyword(s):  
Macrocyclic Ligand ◽  
Host Lattice ◽  
Macrocyclic Complex ◽  
Monoclinic Space Group ◽  
Cyanide Complex ◽  
New Host ◽  
Space Group

Crystals of a new clathrate [CuII(hmtd)CuI(CN)3]·CH2Cl2 were afforded from a Me2CO-EtOH-CH2Cl2 solution of a macrocyclic complex CuII(hmtd)CuI(CN)3·2 H2O (hmtd = 5,7,7,12,14,14-hexamethyl- 1,4,8,11-tetraazacyclotetradeca- 4,11-diene). It crystallizes in the monoclinic space group P21/n, a = 7.936(5), b = 18.717(4), c = 17.783(6) Å, β = 98.55(4)°, Z = 4, R = 0.0558 for 1 870 reflections. Unprecedentedly, only one of the three nitrogen-ends of a CuI(CN)3 moiety is coordinated to the square-pyramidal Cu(II) center. The guest CH2Cl2 molecules are captured in the channel between the potlid-shaped [CuII(hmtd)CuI(CN)3] molecules.

Silyl–Hydrosilane Exchange at a Magnesium Triphenylsilyl Complex Supported by a Cyclen-DerivedNNNN-Type Macrocyclic Ligand

2017 ◽  
Vol 56 (24) ◽  
pp. 14979-14990 ◽  
Author(s):  
Lara E. Lemmerz ◽  
Valeri Leich ◽  
Daniel Martin ◽  
Thomas P. Spaniol ◽  
Jun Okuda
Keyword(s):  
Macrocyclic Ligand

Crystal structure of a PrIII complex with a novel macrocyclic ligand

Polyhedron ◽  
1997 ◽  
Vol 16 (15) ◽  
pp. 2697-2700 ◽  
Author(s):  
Janfang Ma ◽  
Chunji Niu ◽  
Shulan Meng ◽  
Yonghua Lin ◽  
Yan Xing ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Macrocyclic Ligand
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