Another point of interest is that the absorption and emission
properties of the compounds are strongly influenced by the
polarity as well as with the extent of hydrogen bonding ability
of the solvents. This opens the possibility of the application of
such compounds as solvatochromic probes.
Acknowledgements
Financial assistance received from the Department of Science and
Technology, New Delhi [Grant No. SR/S1/IC-33/2010] and the
Council of Scientific and Industrial Research, New Delhi, India
[Grant No. 01(2084)/06/EMR-II], is gratefully acknowledged.
Thanks are due to the DST for providing the single crystal X-
ray difractometer in FIST and the Time-Resolved Nanosecond
Spectrofluorimeter in PURSE programme at the Department of
Chemistry of Jadavpur University. C.B., S.D. and D.M thank
CSIR for their fellowship.
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3
3
the emitting MLCT state and the deactivating MC level. The
important outcome of this study is to increase the energy level
3
separation of the two states by modulating the MLCT energy
level of the complexes by introducing an extensively delocalized
triphenyl-imidazole group in the 4¢-position of the tpy unit,
while keeping the energy of the 3MC state essentially unchanged.
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The Royal Society of Chemistry 2012
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