Electronic Properties of Poly‐Yne Carbon Chains and Derivatives with Transition Metal End‐Groups

Gendron, Frédéric; Groizard, Thomas; Guennic, Boris Le; Halet, Jean‐François

doi:10.1002/ejic.201901112

Cited by 22 publications

(18 citation statements)

References 173 publications

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“…Metal alkynyl complexes have been an attractive target for both synthetic and material chemists since the pioneering work of Nast and subsequent development in polymerization by Hagihara . Exploration of novel alkynyl complexes based on transition metals has remained topical as evidenced by many comprehensive reviews that have appeared during the ensuing decades. − Both the extended conjugation and structural rigidity of metal-oligoynes render them appealing candidates for opto-electronic materials, − molecular wires, − and active species for molecular devices. − It is noteworthy that many of the efforts mentioned above have been based on 4 d and 5 d metals such as Ru, Re, Ir, and Pt, which are rare and precious metals. To transform these interesting properties and functions into technological applications, surrogates based on earth abundant elements are desired.…”

Section: Introductionmentioning

confidence: 99%

A Series of Mono- and Bis-Alkynyl Co(III) Complexes Supported by a Tetra-imine Macrocyclic Ligand (TIM)

et al. 2021

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Reported herein is the synthesis and characterization of a series of monoand bis-alkynyl Co III (TIM) complexes, where TIM is 2,3,9,10-tetramethyl-1,4,8,11tetraazacyclotetradeca-1,3,8,10-tetraene. The trans-[Co(TIM)(C 2 Ar)Cl] + type complexes (Ar = phenyl (Ph, 1a), naphthalene (Np, 1b), and -C 6 F 5 (1c)) were prepared by the addition of HC 2 Ar to trans-[Co(TIM)Cl 2 ]PF 6 in the presence of Et 3 N. Treatment of the mono-alkynyl complexes with AgOTf in MeCN resulted in the trans-[Co(TIM)(C 2 Ar)-(NCMe)](OTf) 2 complexes (Ar = Ph (2a), Np (2b), and -C 6 F 5 (2c)). Complexes 2a and 2b react with the respective HC 2 Ar ligand in the presence of Et 3 N to afford the symmetrical bis-alkynyl complexes trans-[Co(TIM)(C 2 Ar) 2 ] + (Ar = Ph (3a) and Np (3b)). trans-[Co(TIM)(C 2 C 6 F 5 ) 2 ] + (3c) was obtained directly from the prolonged reaction of trans-[Co(TIM)Cl 2 ]PF 6 with HC 2 C 6 F 5 . Furthermore, the addition of HC 2 Ph to 2c in the presence of a weak base yielded the unsymmetrical bis-alkynyl complex trans-[Co(TIM)(C 2 C 6 F 5 )(C 2 Ph)]OTf (4). Molecular structures of complexes 1a/b, 2a/b, [3a]PF 6 , 3b, and 4 were established through single crystal X-ray diffraction. The absorption spectra for 1−4 display d−d bands between 380 and 470 nm. Complexes 1b−3b exhibited Np-based fluorescence. Electrochemical studies revealed that all complexes display an irreversible reduction characteristic of the Co III center, as well as up to two irreversible reduction(s) localized on the TIM macrocycle.

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Section: Introductionmentioning

confidence: 99%

A Series of Mono- and Bis-Alkynyl Co(III) Complexes Supported by a Tetra-imine Macrocyclic Ligand (TIM)

et al. 2021

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“…Following the seminal work on organometallic σ-alkynyl complexes by Nast and co-workers, , considerable attention has been given to the application of these compounds as electronic and optoelectronic materials due to their structural rigidity and high degree of conjugation. − In particular, the use of metal alkynyls as the prototypical molecular wires has been investigated by the laboratories of Launay, , Gladysz, , Halet, , Rigaut, and Akita . Compounds exhibiting extraordinary degrees of electron delocalization include those of Fe, Mn, Ru, Ru 2 , − and Re. , Though rare, single-molecule conductance has been measured for alkynyl compounds of Pt, , Ru, − and Ru 2 , , and functional devices have been fabricated as well. − …”

Section: Introductionmentioning

confidence: 99%

Improving Redox Reversibility and Intermetallic Coupling of Co(III) Alkynyls through Tuning of Frontier Orbitals

2020

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Reported herein are the syntheses and characterizations for a series of butadiyndiyl-bridged Co III (MPC) (MPC = 5,4,8, complexes, capped with chloride ([1] 2+ ), phenylacetylide ([2] 2+ ), or 3,5-dichlorophenylacetylide ([3] 2+ ). The MPC ligand was chosen to weaken the ligand field around the equatorial plane, allowing stronger axial coordination. Cyclic voltammetry measurement revealed the first unambiguous examples of stepwise one-electron reductions in bridged Co(cyclam′) complexes (cyclam′ = any ligand bearing the 1,4,8,11-tetraazacyclotetradecane framework). Further voltammetric analysis using NBu 4 BArF (NBu 4 BArF = tetrabutylammonium tetrakis [3,5-bis(trifluoromethyl)phenyl]borate) as electrolyte resulted in well-separated reversible reduction waves with up to 160 mV separation for [2] 2+ . These features hint at the possibility of application of earth-abundant metal complexes to function as molecular wires. These complexes were also characterized with infrared and UV−vis spectroscopy, density functional theory calculations, and single-crystal X-ray diffraction ([1](BPh 4 ) 2 only).

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“…The chemistry of transition metal alkynyls has evolved extensively since the early study of homoleptic complexes [M(CCR) m ] n − by Nast and co-workers . In addition to continuous interest in new synthesis − and understanding of structures and bonding of metal alkynyls, − recent decades have witnessed significant progress in areas such as molecular electronic wires and devices − and optoelectronic materials . One of the peculiar attributes of metal alkynyl complexes is the propensity to form an η 2 -adduct of Cu(I)/Ag(I) at the acetylenic unit that bonds to the metal center (Chart ), and it has been demonstrated that the η 2 -coordination of Cu(I) attenuates the electronic coupling between two Ru(II) centers linked by butadiynyl …”

Section: Introductionmentioning

confidence: 99%

Co(cyclam) Complexes of Triarylamine-acetylide: Structural and Spectroscopic Properties and DFT Analysis

et al. 2020

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Reported herein are the syntheses of mono-and bis-C 2 TPA (HC 2 TPA = 4-ethynyl-N,N-bis(4-methoxyphenyl)aniline) complexes of Co III (cyclam) (cyclam = 1,4,8,11-tetraazacyclotetradecane) complexes, and the formation of η 2 -adducts of Cu(I)/Ag(I) to the acetylenic bond of TPAC 2 ligand. The reaction between trans-[Co(cyclam)Cl 2 ]Cl and HC 2 TPA in the presence of Et 2 NH yielded trans-[Co(cyclam)(C 2 TPA)Cl]Cl ([1]Cl) and subsequent treatment of [1]Cl with CuCl or AgNO 3 afforded trans-[Co(cyclam)(C 2 TPAη 2 -CuCl 2 )Cl] (2a) or trans-[Co(cyclam)(C 2 TPA-η 2 -Ag(NO 3 ) 2 )(NO 3 )] (2b), respectively. The reaction between [Co(cyclam)Cl 2 ]Cl and 3 equiv of LiC 2 TPA afforded trans-[Co(cyclam)(C 2 TPA) 2 ]Cl ([3]Cl). X-ray diffraction studies of compounds [1]Cl, 2a/b, and [3]Cl established their molecular structures. All four compounds display redox couples that are characteristic of TPA (reversible oxidation) and Co III (irreversible reduction) center. The reversible TPA oxidation in compounds [1]Cl and [3]Cl enables further UV−vis/near-IR spectroelectrochemical studies to elucidate the change of electronic structures upon oxidation. The electronic spectra of both compounds [1]Cl and [3]Cl and their oxidized derivatives have been rationalized based on DFT and TD-DFT analysis.

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Electronic Properties of Poly‐Yne Carbon Chains and Derivatives with Transition Metal End‐Groups

Cited by 22 publications

References 173 publications

A Series of Mono- and Bis-Alkynyl Co(III) Complexes Supported by a Tetra-imine Macrocyclic Ligand (TIM)

A Series of Mono- and Bis-Alkynyl Co(III) Complexes Supported by a Tetra-imine Macrocyclic Ligand (TIM)

Improving Redox Reversibility and Intermetallic Coupling of Co(III) Alkynyls through Tuning of Frontier Orbitals

Co(cyclam) Complexes of Triarylamine-acetylide: Structural and Spectroscopic Properties and DFT Analysis

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