Highly conjugated (polypyridyl)metal-(porphinato)zinc(II) compounds: Long-lived, high oscillator strength, excited-state absorbers having exceptional spectral coverage of the near-infrared

Transient dynamical studies of ruthenium(II) [5-(4′-ethynyl-(2,2′;6′,2″-terpyridinyl))-10,20-bis(2′,6′-bis(3,3-dimethyl-1-butyloxy)phenyl)porphinato]zinc(II)-(2,2′;6′,2″-terpyridine)2+ bis-hexafluorophosphate (Ru-PZn), osmium(II) [5-(4′-ethynyl-(2,2′;6′,2″-terpyridinyl))-10,20-bis(2′,6′-bis(3,3-dimethyl-1-butyloxy)phenyl)porphinato]zinc(II)-(2,2′;6′,2″-terpyridine)2+ bis-hexafluorophosphate (Os-PZn), ruthenium(II) [5-(4′-ethynyl-(2,2′;6′,2″-terpyridinyl))-15-(4′-nitrophenyl)ethynyl-10,20-bis(2′,6′-bis(3,3-dimethyl-1-butyloxy)phenyl)porphinato]zinc(II)-(2,2′;6′,2″-terpyridine)2+ bis-hexafluorophosphate (Ru-PZn-A), osmium(II) [5-(4′-ethynyl-(2,2′;6′,2″-terpyridinyl))-15-(4′-nitrophenyl)ethynyl-10,20-bis(2′,6′-bis(3,3-dimethyl-1-butyloxy)phenyl)porphinato]zinc(II)-(2,2′;6′,2″-terpyridine)2+ bis-hexafluorophosphate (Os-PZn-A), and ruthenium(II) [5-(4′-ethynyl-(2,2′;6′,2″-terpyridinyl))-ruthenium(II)-15-(4′-ethynyl-(2,2′;6′,2″-terpyridinyl))-10,20-bis(2′,6′-bis(3,3-dimethyl-1-butyloxy)phenyl)porphinato]zinc(II)-bis(2,2′;6′,2″-terpyridine)4+ tetrakis-hexafluorophosphate (Ru-PZn-Ru), and ruthenium(II) [5-(4′-ethynyl-(2,2′;6′,2″-terpyridinyl))-osmium(II)-15-(4′-ethynyl-(2,2′;6′,2″-terpyridinyl))-10,20-bis(2′,6′-bis(3,3-dimethyl-1-butyloxy)phenyl)porphinato]zinc(II)-bis(2,2′;6′,2″-terpyridine) tetrakis-hexafluorophosphate (Ru-PZn-Os) show that these highly conjugated supermolecular chromophores feature electronically excited states that absorb over broad NIR spectral windows with considerable oscillator strength and manifest lifetimes (1-50 μs) that are extraordinarily long relative to those of classic low band-gap organic materials. The excited-state absorptive domains of these strongly coupled multipigment ensembles can be extensively modulated. For sequential one-photon absorptive processes, these compounds evince large σe, σe/σg, and σe - σg values. As the combination of all these properties within single chromophoric entities have heretofore lacked precedent within the NIR, these and closely related structures may find particular utility in a variety of technologically important optical-limiting applications. Copyright © 2004 American Chemical Society.