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 (4)] 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, 5, 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 sigma* orbitals. Crystal data for 4 : triclinic, space group P (1) over bar, a = 9.1483(1) Angstrom, b = 9.4868(1) Angstrom, c = 12.9776(2) Angstrom, alpha = 70.614(8)degrees, beta = 85.738(9)degrees, gamma = 83.094(9)degrees, V = 1054.0(2) Angstrom(3), Z = 2, R = 0.0420. Crystal data for 5 : monoclinic, space group P2(1)/c, a = 11.9498(1) Angstrom, b = 11.4695(1) Angstrom, c = 13.9456(8) Angstrom, beta = 104.536(6)degrees, V = 1850.2(3) Angstrom(3), Z = 4, R = 0.0375. Crystal data for 6 : monoclinic, space group P2(1)/n, a = 9.4991(5) Angstrom, b = 23.455(4) Angstrom, c = 9.726(1) Angstrom, beta = 100.629(8)degrees, V = 2129.8(4) Angstrom(3), Z = 4, R = 0.0406. Crystal data for 8 : orthorhombic, space group P2(1)2(1)2(1), a = 9.713(3) Angstrom, b = 9.835(4) Angstrom, c = 13.310(3) Angstrom, V = 1273.8(5) Angstrom(3), Z = 4, R = 0.0695. Crystal data for 9 : orthorhombic, space group P2(1)2(1)2(1), a = 9.7140(3) Angstrom, b = 10.0196(1) Angstrom, c = 13.444(3) Angstrom, V = 1308.5(3) Angstrom(3), Z = 4, R = 0.0320. Crystal data for 11 : monoclinic, space group P2(1)/c, a = 7.9455(7) Angstrom, b = 19.3949(3) Angstrom, c = 8.6226(9) Angstrom, beta = 93.338(9)degrees, V = 1326.5(2) Angstrom(3), Z = 4, R = 0.0379.