Synthesis and Structures of Intramolecularly Base-Coordinated Group 15 Aryl Halides

Four group 15 monochlorides of the type EAr2Cl
[Ar = 2-[(dimethylamino)methyl]phenyl,
2-(Me2NCH2)C6H4
(C9H12N), E = Sb (4), E = Bi
(5); Ar = 8-(dimethylamino)-1-naphthyl,
8-(Me2N)C10H6
(C12H12N), E = Sb
(6),
E = Bi (7)] have been prepared via the salt
elimination reactions of 2 equiv of either
2-(Me2NCH2)C6H4Li
or
8-(Me2N)C10H6Li with
ECl3. Four related group 15 dihalides of the type
EArX2 [Ar =
8-(Me2N)C10H6, X =
Cl,
E = As, (8), E = Sb (9); Ar =
2-(Me2NCH2)C6H4,
X = Cl, E = Bi (10); X = I, E = Bi (11)]
have been prepared
via the salt elimination reactions of equimolar amounts of
8-(Me2N)C10H6Li or
2-(Me2NCH2)C6H4Li
with EX3.
The X-ray crystal structures of 4−6,
8, 9, and 11 are described, and the
observed trends in the degree of
intramolecular coordination of the nitrogen atoms are consistent with
the view that the Lewis acidity of these
complexes is associated with the E−X σ* orbitals. Crystal data
for 4:  triclinic, space group P1̄,
a = 9.1483(1)
Å, b = 9.4868(1) Å, c =
12.9776(2) Å, α = 70.614(8)°, β =
85.738(9)°, γ = 83.094(9)°, V =
1054.0(2) Å3, Z
= 2, R = 0.0420. Crystal data for 5: 
monoclinic, space group P21/c,
a = 11.9498(1) Å, b = 11.4695(1)
Å, c
= 13.9456(8) Å, β = 104.536(6)°, V =
1850.2(3) Å3, Z = 4, R =
0.0375. Crystal data for 6:  monoclinic,
space
group P21/n, a =
9.4991(8) Å, b = 23.455(4) Å, c =
9.726(1) Å, β = 100.629(8)°, V =
2129.8(4) Å3, Z = 4,
R = 0.0406. Crystal data for 8: 
orthorhombic, space group
P212121, a
= 9.713(3) Å, b = 9.835(4) Å, c
=
13.310(3) Å, V = 1273.8(5) Å3,
Z = 4, R = 0.0695. Crystal data for
9:  orthorhombic, space group
P212121,
a
= 9.7140(3) Å, b = 10.0196(1) Å,
c = 13.444(3) Å, V = 1308.5(3)
Å3, Z = 4, R = 0.0320.
Crystal data for 11: 
monoclinic, space group P21/c,
a = 7.9455(7) Å, b = 19.3949(3)
Å, c = 8.6226(9) Å, β = 93.338(9)°,
V =
1326.5(2) Å3, Z = 4, R =
0.0379.