From Salicylaldehyde to Chiral Salen Sulfonates – Syntheses, Structures and Properties of New Transition Metal Complexes Derived from Sulfonato Salen Ligands

Abstract

Coordination complexes derived from chiral and nonchiral sulfonato salen ligands {(SalenSO3)Na2: N,N′‐bis(5‐sulfonatosalicylidene)‐1,2‐diaminoethane disodium salt, [(R,R) and (S,S)‐CySalenSO3]NaK: (R,R) and (S,S)‐N,N′‐bis(5‐sulfonatosalicylidene)‐1,2‐diaminocyclohexane sodium–potassium salt} have been synthesized. The crystal structures of the chiral and nonchiral NiII complexes [Ni(SalenSO3)]Na2 (1) and [Ni((R,R)CySalenSO3)]NaK (2) were solved. The other chiral and nonchiral sulfonato salen complexes, [Cu(SalenSO3)]Na2 (4), [Cu((R,R)CySalenSO3)]NaK (5), [Cu((S,S)CySalenSO3)]NaK (6) and [Zn(SalenSO3)]Na2 (7) got hydrolyzed before suitable crystals could form. Yet, their hydrolysis led to the formation of single crystals of the residues of total or partial hydrolysis: 5‐sulfonatosalicylaldehyde sodium salt (A), N‐(5‐sulfonatosalicylidene)‐1,2‐diaminoethane copper(II) [Cu(SalSO3)] (8) and (R,R)‐N‐(5‐sulfonatosalicylidene)‐1,2‐diaminocyclohexane copper(II) {Cu[(R,R)CySalSO3]} (9). All compounds were studied with IR and UV/Vis spectroscopy; chiral compounds were also investigated by circular dichroism. The magnetic properties of the copper compounds were investigated. Whereas 8 shows intermolecular antiferromagnetic interactions between mononuclear CuII complexes, 7 presents a weak intramolecular ferromagnetic coupling (J = 0.66 cm–1, H = –JŜCu1ŜCu2), which has been rationalized by DFT calculations.

Functional Hybrid Materials Based on Layered Simple Hydroxide Hosts and Dicarboxylate Schiff Base Metal Complex Guests

“…[85,86] This difference is merely a result of the higher spin density along the C-C bond of the carboxylates than along the C-S bond of the sulfonates within the anchoring moieties. These complexes were successfully inserted and grafted into copper and cobalt LSHs.…”

Hybrid interfaces in layered hydroxides: magnetic and multifunctional superstructures by design

“…[142,143] Brought to you by | Stockholms Universitet Authenticated Download Date | 8/15/15 9:13 PM involving different diamine bridges. [140,144,145] The insertion of such complexes generates specific difficulties due to their possible hydrolysis during the exchange reaction. [144] This difficulty has been overcome by working from (Figure 21).…”

“…[140,144,145] The insertion of such complexes generates specific difficulties due to their possible hydrolysis during the exchange reaction. [144] This difficulty has been overcome by working from (Figure 21). The cobalt compounds, noted MPcTS 0 @Co, have a ferrimagnetic behavior ( Figure 22) with Brought to you by | Stockholms Universitet Authenticated Download Date | 8/15/15 9:13 PM ordering temperatures of 5.8, 6.8 and 7.8 K for the compounds functionalized by the Co, Ni and Cu phthalocyanine, respectively.…”

Zn‐Mediated Synthesis of 3‐Substituted Indoles Using a Three‐Component Reaction Approach

“…[4] Zhou and coworkers reported that water-soluble Cu(salphen)s [salphen = N,NЈ-bis(salicylidene)imine-1,2-phenylenediamine] in the presence of a suitable base are excellent catalysts for converting various combinations of aldehydes, malononitrile and indoles into the respective 3-component reaction (3-CR) products (Scheme 1) and provide high yields by using water as the 4694 benzylidene malononitrile species. [7] This stability issue therefore raises the question as to whether or not water is truly the best solvent for this 3-CR process since the organic products needed to be isolated and purified by using organic solvents. The results led to a mechanistic proposal in which the benzylidene malononitrile intermediate plays a central role; it is one of the major species that is formed in most of the catalytic reactions studied.…”

“…Therefore, we envisioned that the use of Zn II ‐ rather than Cu II ‐salphen complexes would be beneficial for effective synthesis of the 3‐substituted indoles. It is worth noting that recent work has shown that Cu‐ and Zn(salen)s have a tendency to decompose under aqueous conditions to provide access to “half‐salen” type intermediates 7. This stability issue therefore raises the question as to whether or not water is truly the best solvent for this 3‐CR process since the organic products needed to be isolated and purified by using organic solvents.…”