Ionic 4,4‘-Biphenylene-Bridged Bis-ruthenium Complexes [Ru₂(4,4‘-{C₆H₂(CH₂NMe₂)₂-2,6}₂)(terpy)₂]ⁿ⁺ (n = 2 and 4) and Their Reversible Redox Interconversion:  A Molecular Switch

Abstract

Copper(II)-mediated oxidative coupling of the blue, 18-electron mononuclear complex [Ru II -{C 6 H 3 (CH 2 NMe 2 ) 2 -2,6}(terpy)]Cl, 3 (terpy ) 2,2′;6′,2′′-terpyridine), affords the unique diamagnetic, binuclear 34-electron complex [(Ru III ) 2 (4,4′-{C 6 H 2 (CH 2 NMe 2 ) 2 -2,6} 2 )(terpy) 2 ]-(CuCl 2 ) 4 , 5a. This intensely green complex has been the subject of an X-ray crystal structure determination, and the molecular geometry of the tetracation shows the C4-C4′-coupled bridging biphenylene dianion to be planar. Two-electron reduction of this tetracation as its PF

Thermodynamics of Pyridine Coordination in 1,4-Phenylene Bridged Bimetallic (Pd, Pt) Complexes Containing Two N,C,N‘ Motifs, 1,4-M2-[C6(CH2NR2)4-2,3,5,6]

“…Deuterated pyridine (13d-d 5 ) was added to the solution to give a final concentration of 20 mM in 13d-d 5 . The solution was inverted several times in the NMR tube to mix the reactants, and the sample was returned to the spectrometer.…”

“…The concise synthesis of bimetallic complexes 3 and 5, reported previously by van Koten, established that their preparation could be realized on a gram scale (Scheme 1). [5][6][14][15] To take full advantage of the attractive characteristics of the 1,4-phenylene bridged complexes in the study of bulk materials, the thermodynamics and kinetics of reversible ligand coordination, particularly those of pyridine derivatives, must be quantified. Although coordination complexes between substituted pyridines and Pd(II) and Pt(II-containing organometallic species have a considerable presence in a range of thermodynamically 22 and kinetically 23-24 controlled assembly processes, we are unaware of more than a few published thermodynamic data 22 for these associations in pincer motifs.…”

Synthesis of novel terdentate N,C,N′-coordinated butyltin(IV) complexes and their redistribution reactions with SnCl4

“…The difference in reactivity is ascribed to the increase in electron density at the tin(IV) center by the donor substituent [5,6] monoanionic aryldiamine ligand [C 6 H 3 (CH 2 NMe 2 ) 2 -2,6] À (NCN) and studied their structure in solution as well as in the solid state [7]. The NCN pincer ligand has been employed for many years in our group to prepare a wide range of organometallic complexes of which some have been applied successfully as catalysts [8], sensors [9], and switches [10].…”

Organic Transformations on σ‐Aryl Organometallic Complexes

“…Nearly simultaneously with the publication by Sauvage and co-workers, van [65] The mechanism of this process clearly involves activation of the aromatic C À H bond of the NCN pincer ligand in 86 that is para-positioned with respect to the Ru À C ipso s bond. However, the fact that the C À C coupling reaction does not take place in the absence of Cu II , or in aqueous medium, led to the conclusion that the mechanism of the reaction must involve heteronuclear organocopper intermediates.…”

“…However, the simultaneous formation of the chloro-functionalized complexes 88 and 93 indicates that the para positions in 86 and 91 are somewhat activated towards substitution, similarly to other cyclometalated Ru II compounds presented in the previous sections of this review (Section 3). The photophysical and redox properties of the dimetallic complexes 84, [64] 85, [64] 87, [65] and 92 [68] and of the mixed-valence species generated from their partial oxidation or reduction, have been subject of detailed studies. However, to the best of our knowledge, the metal-mediated oxidative CÀC coupling with unfunctionalized organonometallic substrates is a synthetic approach still relatively unexplored.…”