Ruthenoarenes versus phenol derivatives as axial linkers for subporphyrazine dimers and trimers.
The subporphyrazine (SubPz) dimer diboron(III) [μ-1',4'-benzenediolato][bis-(1,2,6,7,11,12-hexapropylsubporphyrazinato)] (2) and trimer triboron(III)[μ-1',3',5'-benzenetriolato][tris-(1,2,6,7,11,12-hexapropylsubporphyrazinato)] (4), consisting of SubPz units assembled through their axial positions by hydroquinone- and phloroglucinol-linkers, respectively, have been prepared. Selective ruthenium-π-coordination to the linking aromatic rings afforded SubPz arrays 8 and 9, respectively. These latter systems displayed different degrees of electronic communication between the macrocycles relative to 2 and 4 as inferred from analyses of the ground- and excited-state features. For instance, as revealed by time-resolved pump probe transient absorption spectroscopy, the excited singlet states of dimer 2 and trimer 4 undergo rather rapid deactivation. In contrast, the presence of a ruthenoarene linker, as in 8 and 9, serves to increase the SubPz singlet excited state lifetimes; these now reach values similar to those seen in the case of monomeric SubPz compounds that either do or do not contain ruthenoarene subunits (i.e., 7 and 6, respectively). These findings are ascribed to the redox active nature of the hydroquinone and phloroglucinol linkers in 2 and 4 and a change in the electronics that results from organometallic functionalization.
Departamento de Química Orgánica, Universidad Autónoma de Madrid, Cantoblanco, 28049-Madrid (Spain), Fax: (+34) 914974151.
Esmeralda
E
Caballero
Carlos
C
Romero-Nieto
Volker
V
Strauß
M Salomé
MS
Rodríguez-Morgade
Dirk M
DM
Guldi
Jonathan L
JL
Sessler
Tomás
T
Torres
D004563:Electrochemistry; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010636:Phenols; D011108:Polymers; D012428:Ruthenium / Q000737:chemistry*
D009942:Organometallic Compounds; D010636:Phenols; D011108:Polymers; D012428:Ruthenium
cyclopentadienyl ligands; electrochemistry; macrocycles; pi interactions; ruthenium