J. Li et al., MULTIFUNCTIONAL LIGANDS - PHOSPHINIMINE-SUBSTITUTED CYANOFLUOROAROMATICS INCLUDING X-RAY MOLECULAR-STRUCTURES OF 3 REPRESENTATIVE LIGANDS 4,6-(CN)(2)C6F2-1,3-(N=PPH(3))(2), 4,6-(CN)(2)C6F2-1,3-(N=PPH(2)ME)(2) AND 4,6-(CN)(2)C6F(2)-1-(N=PPH(3))-3-(N=PPH(2)ME) - FORMATION OF RHODIUM(I) COMPLEXES, Inorganic chemistry, 35(19), 1996, pp. 5684-5692
Reaction of 1,3-dicyanotetrafluorobenzene with 2 equiv of (trimethylsi
lyl)iminophosphoranes gave the disubstituted derivatives 4,6-(CN)(2)C6
F2-1,3-AB: 1, A = B = (N=PPh(3)); 2, A = B = (N=PPh(2)Me); and 3, A =
(N=PPh(3)), B = (N=PPh(2)Me). Monosubstituted compounds of the type 2,
4-(CN)(2)C6F3-1-A; notably 4, A = (N=PPh(3)), and 5, A = (N=PPh(2)Me),
were readily obtained by reaction of 1 molar equiv of the silylated i
minophosphorane with the cyanofluoro aromatic. Substitution of the flu
orine para to the CN group(s) occurs in all cases. Reactions of 1,2- a
nd 1,4-dicyanotetrafluorobenzene with (trimethylsilyl)iminophosphorane
s gave only monosubstituted derivatives 3,4-(CN)(2)C6F3-1-A (6, A = (N
=PPh(3)), and 7, A = (N=PPh(2)Me)) and 2,5-(CN)(2)C6F3-1-A (8, A = (N=
PPh(3)), and 9, A = (N=PPh(2)Me)), respectively, as the result of elec
tronic deactivation of the second substitutional point. 1, 4,6-(CN)(2)
C6F2-1,3-(N=PPh(3)), 2, 4,6-(CN)(2)C6F2-1,3-(N=PPh(2)Me)(2), and 3, 4,
6-(CN)(2)C6F2-1-(N=PPh(3))-3-(N=PPh(2)Me) have been structurally chara
cterized. For 1 (at 21 degrees C), monoclinic, C2/(c), (No. 15), a = 1
5.289(2) Angstrom, b = 10.196(1) Angstrom, c = 23.491(6) Angstrom, bet
a = 91.63(2)degrees, V = 3660(2) Angstrom(3), and Z = 4. The P=N bond
length is 1.579(2) Angstrom and the P-V-N-C(phenyl) angle is 134.0(2)d
egrees. For 2, (at 21 degrees C) monoclinic, C2/(c) (No. 15), a = 18.6
94(2) Angstrom, b = 8.576(1) Angstrom, c = 40.084(4) Angstrom, beta =
94.00(1)degrees, V = 6411(2) Angstrom(3), and Z = 8. The P(1)=N(1) bon
d length is 1.570(4) Angstrom, the P(2)=N(2) bond length is 1.589(3) A
ngstrom, the P(1)-N(1)-C(14) angle is 131.6(3)degrees, and the P(2)-N(
2)-C(16) angle is 131.3(3)degrees. For 3, (at -80 degrees C) monoclini
c, P2(1)/c (No. 14), a = 9.210(1) Angstrom, b = 18.113(2) Angstrom, c
= 20.015(2) Angstrom, beta =100.07(1)degrees, V = 3287(2) Angstrom(3),
and Z = 4. The P(1)=N(1) bond length (PPh(3) group) is 1.567(4) Angst
rom, the P(2)=N(2) bond length (PPh(2)Me group) is 1.581(5) Angstrom,
the P(1)-N(1)-C(1) angle is 140.4(4)degrees, and the P(2)-N(2)-C(3) an
gle is 129.4(4)degrees. These new multifunctional chelating ligands re
adily react with [Rh(cod)Cl](2) and AgClO4 to give cationic Rh(I) comp
lexes in which the imine and/or the nitrile groups are coordinated to
the Rh center.