inorganic chemistry

ReIðÞbpy
ðÞCO 3 Cl

hi


! ReIðÞbpy
ðÞCO 3

hi

þ Cl

$ Re^0 ðÞbpyðÞCO 3



þ Cl

ð 23 Þ

As the active species formed by elimination of the Cl
ligand
possesses the characteristics of a 17-electron species (Eq. 23),

TABLE VIII

PHOTOCATALYTICCO 2 REDUCTIONUSINGfac-[Re(4,4^0 -X 2 bpy)(CO) 3 (PR^03 )]þ,a

REACTION OF THECORRESPONDINGOER SPECIES WITHCO 2 ,ANDTHEIRREDUCTION

POTENTIALS.

[Re(4,4^0 -X2,-bpy)(CO) 3 (PR^03 )]þ

Entry X PR^03 E1/2redb(V) k 1 c(10
^5 M
^1 s
^1 ) FCOd

3d H P(n-Bu) 3
1.39 10.7 0.013
3e H PEt 3
1.39 3.5 0.024
3h H P(Oi-Pr) 3
1.44 94.2 0.20
3a H P(OEt) 3
1.43 56.0 0.16
3i H P(OMe) 3
1.41 60.0 0.17
3b Me P(OEt) 3
1.55 186 0.18
3c CF 3 P(OEt) 3
1.03 5.2 0.005

Adapted with permission from Ref.( 65 ). Copyright 1997 American Chemical Society.

aA DMF-TEOA (5:1 v/v) solution containing a complex (2.6 mM) was irradiated at

365 nm (light intensity, 1.27 10 
^8 einstein s
^1 ).

bReduction potentials of the complexes versus Ag/AgNO 3.

cSecond-order reaction rate constants of the OER species and CO 2 (0.139 M).

dQuantum yield of CO formation.

TABLE IX

PHOTOPHYSICAL ANDELECTROCHEMICALPROPERTIES OFRHENIUMCOMPLEXES.

Complex

lmaxabsa

(nm)

lmaxemb

(nm)

tc

(ns)

E1/2redd

(V) FCOe TNCOf

1a 376 637 25 g
1.67 0.14 15
12 371 635 30
1.61 0.30 30
8 356 611 87
1.67 0 0

Copyright 2008 American Chemical Society.

Adapted with permission from Ref.( 64 )

aAbsorption maxima in DMF.

bEmission maxima in DMF at room temperature.

cExcited state lifetimes in DMF at room temperature under an Ar atmosphere.

dReduction potentials of the complexes versus Ag/AgNO 3.

eQuantum yields of CO formation (365-nm light irradiation with

7.5 10 
^9 einstein s
^1 ).

fTurnover numbers of CO formation.

gin MeCN, Ref. ( 28 ).

174 HIROYUKI TAKEDAet al.