TY - JOUR
T1 - Disassembly of diruthenium(II,III) tetraacetate with P–N donor ligands
AU - Essoun, Ernest
AU - Wang, Ruiyao
AU - Aquino, Manuel A.S.
N1 - Publisher Copyright:
© 2016 Elsevier B.V.
PY - 2017
Y1 - 2017
N2 - Valent-averaged diruthenium(II,III) tetraacetate, [Ru2(μ-O2CCH3)4(H2O)2](PF6), was reacted with various bidentate P–N donor ligands. These reactions led to the partial displacement of bridging carboxylate groups and concomitant cleavage of the Ru–Ru bond, producing novel complexes. Disassembly reactions with the aminophosphines; diphenyl-2-pyridylphosphine (dpppy) and 2-(diphenylphosphino)ethylamine (dppea), produced homoleptic tris-chelated species, fac-[Ru(dpppy-P,N)3](PF6)2(III) and mer-[Ru(dppea-P,N)3](PF6)2(VI), respectively. Disassembly reactions with aromatic aminophosphines; 2-(diphenylphosphino)methylpyridine (dppmpy) and 2-(diphenylphosphino)ethylpyridine (dppepy), led to heteroleptic tris-chelated complexes cis,cis,trans-[Ru(dppmpy-P,N)2(η2-O2CCH3)](PF6)·MeOH (IV) and cis,cis,trans-[Ru(dppepy-P,N)2(η2-O2CCH3)](PF6) (V), respectively, whereas reaction with the non-cyclic aminophosphine, 3-(diphenylphosphino)-1-propylamine (dpppa) and the non-cyclic iminophosphine, 2-(diphenylphosphino)benzylidinebenzylamine (dppbba), led to the heteroleptic tris-chelated complexes cis,cis,trans-[Ru(dpppa-P,N)2(η2-O2CCH3)](PF6·EtOH (VII) and cis,cis,trans-[Ru(dppbba-P,N)2(η2-O2CCH3)](PF6)·2MeOH·H2O (VIII), respectively. All complexes were fully characterized. Electrochemical studies (CV, OSWV) showed that the homoleptic tris-chelated complexes had higher oxidation potentials (Epa) than the corresponding heteroleptic tris-chelated complexes, due to the weak π-acceptor ability of the acetate group. Complex (III) has the highest Epaas it contains the strongest combination of π-accepting groups. The Epavalues of the heteroleptic complexes were found to be in the order: dppbba (CH[dbnd]N) > dppmpy, dppepy (py) > dpppa (NH2), since amines are much poorer π-acceptors than pyridyl and imino groups. Complexes (III), (VI) and (VII) showed irreversible oxidation waves, while complexes (IV), (V) and (VIII) displayed quasi-reversible one electron processes.
AB - Valent-averaged diruthenium(II,III) tetraacetate, [Ru2(μ-O2CCH3)4(H2O)2](PF6), was reacted with various bidentate P–N donor ligands. These reactions led to the partial displacement of bridging carboxylate groups and concomitant cleavage of the Ru–Ru bond, producing novel complexes. Disassembly reactions with the aminophosphines; diphenyl-2-pyridylphosphine (dpppy) and 2-(diphenylphosphino)ethylamine (dppea), produced homoleptic tris-chelated species, fac-[Ru(dpppy-P,N)3](PF6)2(III) and mer-[Ru(dppea-P,N)3](PF6)2(VI), respectively. Disassembly reactions with aromatic aminophosphines; 2-(diphenylphosphino)methylpyridine (dppmpy) and 2-(diphenylphosphino)ethylpyridine (dppepy), led to heteroleptic tris-chelated complexes cis,cis,trans-[Ru(dppmpy-P,N)2(η2-O2CCH3)](PF6)·MeOH (IV) and cis,cis,trans-[Ru(dppepy-P,N)2(η2-O2CCH3)](PF6) (V), respectively, whereas reaction with the non-cyclic aminophosphine, 3-(diphenylphosphino)-1-propylamine (dpppa) and the non-cyclic iminophosphine, 2-(diphenylphosphino)benzylidinebenzylamine (dppbba), led to the heteroleptic tris-chelated complexes cis,cis,trans-[Ru(dpppa-P,N)2(η2-O2CCH3)](PF6·EtOH (VII) and cis,cis,trans-[Ru(dppbba-P,N)2(η2-O2CCH3)](PF6)·2MeOH·H2O (VIII), respectively. All complexes were fully characterized. Electrochemical studies (CV, OSWV) showed that the homoleptic tris-chelated complexes had higher oxidation potentials (Epa) than the corresponding heteroleptic tris-chelated complexes, due to the weak π-acceptor ability of the acetate group. Complex (III) has the highest Epaas it contains the strongest combination of π-accepting groups. The Epavalues of the heteroleptic complexes were found to be in the order: dppbba (CH[dbnd]N) > dppmpy, dppepy (py) > dpppa (NH2), since amines are much poorer π-acceptors than pyridyl and imino groups. Complexes (III), (VI) and (VII) showed irreversible oxidation waves, while complexes (IV), (V) and (VIII) displayed quasi-reversible one electron processes.
KW - Diruthenium(II,III) tetraacetate
KW - P–N donor ligands
KW - Synthetic methodology
KW - X-ray crystallography
UR - http://www.scopus.com/inward/record.url?scp=84958568878&partnerID=8YFLogxK
U2 - 10.1016/j.ica.2016.02.021
DO - 10.1016/j.ica.2016.02.021
M3 - Article
AN - SCOPUS:84958568878
SN - 0020-1693
VL - 454
SP - 97
EP - 106
JO - Inorganica Chimica Acta
JF - Inorganica Chimica Acta
ER -