Efficiency of intersystem crossing to the lowest excited state of chromium polypyridyls determined by using pulsed photoacoustic microcalorimetry

Journal Article · Wed Jun 15 04:00:00 EDT 1988 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic00285a033· OSTI ID:5776299

Lynch, D; Endicott, J F

A simple photoacoustic detection system for determining intersystem crossing yields, /Phi//sub isc/, of inorganic systems is described. Values found for /Phi//sub isc/ of Cr(bpy)/sub 3//sup 3+/, Cr(phen)/sub 3//sup 3+/, Cr(5-Cl-phen)/sub 3//sup 3+/, and Cr(4,4'-Me/sub 2/bpy)/sub 3//sup 3+/ are 0.93, 0.95, 0.73, and 1.04, respectively. This is in excellent agreement with the reported values of 0.95-1.0 for Cr(bpy)/sub 3//sup 3+/ based on other techniques. This technique has also been used to determine that there are long-lived (/tau/ > 10 ns) upper excited states or other high-energy species produced that prevent rapid relaxation to the /sup 2/E//sup 2/T manifold following excitation of Cr(4,7-Ph/sub 2/phen)/sub 3//sup 3+/ and Cr(4,7-Me/sub 2/phen)/sub 3//sup 3+/. Without resorting to deconvolution techniques, this method can be used on systems that have rapid relaxation (/tau/ < 1 ns) of the upper excited states and lifetimes > 5 /mu/s for the lowest energy state when a 5-MHz transducer is used for detection of the photoacoustic signal. 15 references, 7 figures, 1 table.

• Research Organization: Wayne State Univ., Detroit, MI (USA)
• OSTI ID: 5776299
• Journal Information: Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 27:12; ISSN INOCA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical &amp; Physicochemical Properties
CALORIMETRY
CHROMIUM COMPOUNDS
DATA
ENERGY LEVELS
EXCITED STATES
EXPERIMENTAL DATA
HETEROCYCLIC COMPOUNDS
INFORMATION
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANOMETALLIC COMPOUNDS
PHOTOACOUSTIC EFFECT
TRANSITION ELEMENT COMPOUNDS