Comparison of the Structure and Stability of New α-Diimine Complexes of Copper(I) and Silver(I): Density Functional Theory versus Experimental

Abstract

New compounds of the general formulas [M(Ar-BIAN)(2)]BF(4) and [M(Ar-BIAN)(NCMe)(2)]BF(4), where M = Cu(I) or Ag(I) and Ar-BIAN = bis(aryl)acenaphthenequinonediimine, were synthesized by the direct reaction of [Cu(NCMe)(4)]BF(4) or [Ag(NCMe)(4)]BF(4) with the corresponding Ar-BIAN ligand in dried CH(2)Cl(2). The synthesized compounds are [M(o,o',p-Me(3)C(6)H(2)-BIAN)(2)]BF(4) where M = Cu(I) (1) and Ag(I) (2), [M(o,o'-iPr(2)C(6)H(3)-BIAN)(NCMe)(2)]BF(4) where M = Cu(I) (3) and Ag(I) (4), and [Ag(o,o'-iPr(2)C(6)H(3)-BIAN)(2)]BF(4) (5). The crystal structures of compounds 1-3 and 5 were solved by single-crystal X-ray diffraction. In all cases copper(I) or silver(I) are in a distorted tetrahedron that is constructed from the four nitrogen atoms of the two α-diimine ligands or, in 3, from one α-diimine ligand and two acetonitrile molecules. All compounds were characterized by elemental analyses, matrix-assisted laser desorption-ionization time-of-flight mass spectrometry, and IR, UV-vis, and (1)H NMR spectroscopy. The analysis of the molecular geometry and the energetic changes for the formation reactions of the complexes, in a CH(2)Cl(2) solution, were evaluated by density functional theory calculations and compared with the experimental results.

Synthesis, UV–Vis and CV properties of a structurally related series of bis(Arylimino)acenaphthenes (Ar‐BIANs)

“…The energy of this latter band follows a Hammett relationship with a Pearson regression value of R 2 = 0.941, thus implicating the arylimine in the transition; its intensity in 1 is significantly higher than the others in the series. High energy bands are assigned as π‐π* ligand‐centered ( 1 LC) transitions from both the acenaphthene and aryl moieties, similar to the assignments found in the literature for other Ar‐BIANs . We have tentatively assigned the low energy bands to an intraligand charge transfer ( 1 ILCT) between the arylimine and the acenaphthene with some minor 1 LC acenapthene contribution.…”

“…Since the first accounts by Elsevier and van Asselt in the 1990s, numerous transition metal Ar‐BIAN complexes, wherein the Ar‐BIAN acts as a neutral bidentate chelate, have been reported, many of which have been employed in catalysis and olefin polymerization . Their coordination chemistry to main group, transition metals and lanthanides has also been widely explored . We recently reported the first examples of iridium(III) 4‐MeOPh‐BIAN complexes, which serve as promising lead compounds that efficiently absorb light across the visible spectrum .…”

Synthesis and Catalysis of Redox‐Active Bis(imino)acenaphthene (BIAN) Iron Complexes

“…This may explain why, for singly reduced 2 a , 2 c , 2 d , and 5 a , an irreversible electrochemical behavior is observed upon further decrease of the applied potential. However, it should not be concealed that free bis(imino)acenaphthenes very often do not show reversible redox events in cyclovoltammograms …”

“…The UV/Vis spectra of the Fe and Zn complexes and the free ligands were recorded in acetonitrile solution at room temperature. The free R‐BIANs 1 a – g exhibited intense absorptions in the UV region and a broad absorption at around 400 nm, which are commonly assigned to π–π* transitions of the aryl substituents and the acenaphthene backbone and to an intraligand charge transfer, respectively ,. These bands are slightly shifted in the Fe and Zn complexes (Figure , Table S1 in the Supporting Information).…”

MALDI‐TOFMS analysis of coordination and organometallic complexes: a nic(h)e area to work in

“…Since 2005 many other systems have been investigated. These include, but are not limited to, porphyrins and phthalocyanines,26–37 other nitrogen heterocycles,26, 38–46 other nitrogen ligands,47–53 metallocenes/aryl ligands,26, 54–60 phosphorus ligands,26, 44, 57, 59, 61–63 hydrazones,64 carboxylates,51, 54, 65 thiophenes,66, 67 acetylacetonates,59, 68 ethers,69, 70 polyynes/cumulenes,71 acetohydrazides,72 octreotate,73 tripsalen,74 thiols75 and quinolates 76. Successfully characterised compounds have contained, but are not limited to, magnesium,37 the first‐row transition metals in general,63, 68 specifically vanadium,59 chromium,74 manganese,28, 74 iron,26, 35, 40, 54, 59, 60, 63, 66, 74 cobalt,28, 29, 31, 33, 34, 40, 42, 64, 72 nickel,29, 33, 40, 64, 67, 72 copper,26, 29, 31, 33, 34, 39, 52, 64, 71, 72 zinc,26, 28, 29, 31–34, 40, 45, 48, 55, …”