Pm. Frugeri et al., THERMAL AND PHOTOCHEMICAL REACTIVITY OF TETRAAMINERUTHENIUM COMPLEXESCONTAINING 1,3,5-TRIAZA-7-PHOSPHAADAMANTANE AS A LIGAND, New journal of chemistry, 21(3), 1997, pp. 349-354
The k(1) and k(-1) values for the thermal reaction: trans-[Ru(NH3)(4)(
TPA) (TPAH)](3+) + H3O+ (kappa 1)reversible arrow(k-1) trans-[Ru(NH3)(
4)(TPA)(H2O)](3+) + TPAH(+), where TPA = 1,3,5-triaza-7-phosphaadamant
ane, are 1.5 +/- 0.1 M-1 s(-1) and 9.1 +/- 0.5 x 10(-3) s(-1), respect
ively, (at 25.0 +/- 0.1 degrees C, mu = 0.10 mol L-1, pH = 2.6, CF3COO
H). The E-RuIII/RuII(0') in the trans-[Ru(NH3)(4)(TPAH)(H2O)](3+) spec
ies is 0.60 V (vs SCE) in aqueous solution at room temperature (mu = 0
.10 mol L-1/CF3COONa, pH = 2.6/CF3COOH). The electronic spectral chara
cteristics of trans-[Ru(NH3)(4)(TPAH)(H2O)](3+) are lambda = 254 nm, e
psilon = 1.48 x 10(4) M-1 cm(-1) ((1)A(1) --> E-1((1))) and lambda = 3
20 nm, epsilon = 1.40 x 10(3) M-1 cm(-1) ((1)A(1) --> (1)A(2)). The am
monia ligand is photolabilized when trans-[Ru(NH3)(4)(TPAH)H2O](3+) Or
trans-[Ru(NH3)(4)(TPA)H2O](2+) are irradiated, phi(NH3) = 0.32 +/- 0.
04 mol/einstein (CH+ = 1.0 x 10(-3) -1.0 x 10(-6) mol L-1). The substi
tution reaction of pyrazine In trans-[Ru(NH3)(4) (TPAH)(H2O)](3+) proc
eeds at pH = 1.6, with k(1) = 0.17 +/- 0.02 mol(-1) L s(-1) and k(-1)
= 0.033 +/- 0.002 s(-1) and in trans-[Ru(NH3)(4)(TPA)(H2O)](2+) at pH
= 6.2, with k(1) = 0.93 +/- 0.02 mol(-1) L s(-1) and k(-1) = 0.043 +/-
0.002 s(-1) (at 25.0 +/- 0.1 degrees C, mu = 0.10 mol L-1, CF3 COONa/
CF3COOH). An increase in the transition-metal catalyst solubility in w
ater can be achieved by replacing the ETPB and P(OPh)(3) ligands by TP
AH(+) and the P(OCH2CH2Cl)(3), PPh3, dppe, H(2)Pcy and P(OMe)(3) ligan
ds by TPA without any noticeable change in reactivity since their tran
s effects are about the same. In the same way, if the trans influence
is the important factor, the P(OCH2CH2Cl)(3), P(OPh)(3), and dppe liga
nds have about the same trans influence as TPAH(+) and the PPh3 P(OEt)
(3), P(OBut)(3), P(OPrl)(3), P(OBun)(3) and P(OH)(3) ligands about the
same trans influence as TPA.