Syntheses, Characterization and Optical Limiting Properties of Heterometallic Cluster-containing Polymers
Date
2003
Authors
Lucas, Nigel
Notaras, Eleni
Samoc, Marek
Luther-Davies, Barry
Humphrey, Mark
Journal Title
Journal ISSN
Volume Title
Publisher
SPIE - The International Society for Optical Engineering
Abstract
Transition metal carbonyl clusters incorporating group 6 (molybdenum, tungsten) and iridium atoms in a tetrahedral or butterfly-shaped four-atom cluster core, together with carbonyl, cyclopentadienyl and alkyne ligands, have been synthesized and incorporated into oligourethanes, and their optical limiting properties assessed by open-aperture Z-scan (ns pulses, 523 nm) and time-resolved pump-probe studies (ps pulses, 527 nm). The Z-scan studies reveal that the tetrahedral [M2Ir2] cluster cores (M = Mo, W) displayed a greater effective nonlinear absorption coefficent β 2 than the [MoIr3] cores; the tungsten example, W 2Ir2(CO)10(η-C5H 5)5, exhibited the highest response. Substitution at the cyclopentadienyl group (including incorporation into a polymer backbone) had little effect on the response measured. A time-resolved investigation of the alkyne-adduct Mo2Ir2(μ4-η 2-MeC2Ph)(CO)8(η-C5H 4Me)2 using picosecond pulses at 527 nm reveals optical-power-limiting behaviour that results from electronic processes [specifically, a fast nonlinear absorption process followed by reverse saturable absorption involving long-lived (>1000 ps) metastable excited states].
Description
Keywords
Keywords: Electron energy levels; Laser pulses; Light absorption; Nonlinear optics; Oligomers; Photons; Pumping (laser); Synthesis (chemical); Clusters; Optical limiting; Pump-probe experiments; Z-scan measurements; Metallorganic polymers Clusters; Oligomers; Optical limiting; Pump-probe; Z-scan
Citation
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Source
Proceedings of SPIE
Type
Conference paper