Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published August 29, 2012 | Published + Supplemental Material
Journal Article Open

Structural Control of ^1A_(2u)-to-^3A_(2u) Intersystem Crossing in Diplatinum(II,II) Complexes


Analysis of variable-temperature fluorescence quantum yield and lifetime data for per(difluoroboro)tetrakis(pyrophosphito)diplatinate(II) ([Pt_2(μ-P_2O_5(BF_2)_(2)4)]^(4–), abbreviated Pt(pop-BF_2)), yields a radiative decay rate (k_r = 1.7 × 10^8 s^(–1)) an order of magnitude greater than that of the parent complex, Pt(pop). Its temperature-independent and activated intersystem crossing (ISC) pathways are at least 18 and 142 times slower than those of Pt(pop) [ISC activation energies: 2230 cm^(–1) for Pt(pop-BF_2); 1190 cm^(–1) for Pt(pop)]. The slowdown in the temperature-independent ISC channel is attributed to two factors: (1) reduced spin–orbit coupling between the ^1A_(2u) state and the mediating triplet(s), owing to increases of LMCT energies relative to the excited singlet; and (2) diminished access to solvent, which for Pt(pop) facilitates dissipation of the excess energy into solvent vibrational modes. The dramatic increase in E_a is attributed to increased P-O-P framework rigidity, which impedes symmetry-lowering distortions, in particular asymmetric vibrations in the Pt_2(P-O-P)_4 core that would allow direct ^1A_(2u)–^3A_(2u) spin–orbit coupling.

Additional Information

© 2012 American Chemical Society. Received: June 15, 2012. Publication Date (Web): August 6, 2012. We thank Renske van der Veen for interesting discussions. Research at Caltech was supported by the NSF Center for Chemical Innovation (Powering the Planet CHE-0802907 and CHE-0947829) and CSER (Gordon and Betty Moore Foundation). Work at the J. Heyrovský Institute was funded by the Czech Ministry of Education program KONTAKT (grant ME10124).

Attached Files

Published - ja305666b.pdf

Supplemental Material - ja305666b_si_001.pdf


Files (1.5 MB)
Name Size Download all
1.2 MB Preview Download
262.5 kB Preview Download

Additional details

August 19, 2023
October 18, 2023