Lewis-base adducts of lead(II) compounds .7. Synthetic and structural studies of some 1:1 adducts of linear polyamines with lead(II) nitrate

Syntheses and room-temperature single-crystal X-ray structure determinations are recorded for 1:1 adducts of lead(II) nitrate with the linear multidentate polyamines ethane-1,2-diamine ('en' (= '2')), H2N(CH2)(2)NH(CH2)(2)NH2 ('dien' = '22') and H2N(CH2)(x)NH(CH2)(y)NH(CH2)(z)NH2 (zyztet = '222tet' (= 'trien'), '232tet', '323tet'). Crystal/refinement data are as follows: [(en)Pb(NO3)(2)]((infinity/infinity)) is monoclinic, P2(1)/c, a 5.388(2), b 12.440(5), c 13.123(3) Angstrom, beta 102.33(3)degrees, Z = 4 f.u.; R 0.037 for N-o 2698 'observed' (I > 3 sigma(I)) reflections. [(dien)Pb(NO3)(2)]((infinity/infinity)) is orthorhombic, Ccma, a 9.800(2), b 10.840(2), c 20.521(5), Z = 8; R 0.045, N-o 991. [(trien)Pb(NO3)(2)]((infinity/infinity)) is orthorhombic, P2(1)2(1)2(1), a 14.815(3), b 10.975(3), c 8.410(2) Angstrom, Z = 4; R 0.050, N-o 1360; [(232tet)Pb(NO3)(2)]((infinity/infinity)) is isomorphous, a 14.524(6), b 11.221(1), c 8.860(2) Angstrom, R 0.036, N-o 2371. [(323tet)Pb(NO3)(2)]((infinity/infinity)) is monoclinic, P2(1)/c, a 8.195(4), b 14.407(7), c 13.312(4) Angstrom, beta 91.05(3)degrees, Z = 4; R 0.049: N-o 1644. In general, the degree of complexity of the adduct diminishes as the ligand size increases: whereas the en adduct is a compact one-dimensional two-stranded polymer with nearly all nitrate oxygens involved in tight bridging interactions, the extent of bridging diminishes in the adducts of the larger amines, until, for the 323tet species, a monomer is obtained involving a lead coordination sphere containing the ligand and a pair of bidentate nitrate groups. The 1:2 adduct with en is also recorded, and is a dimer with quasi-i internal symmetry. [(en)(2)Pb(NO3)(2)](2) is monoclinic, P2(1), a 6.661(2), b 14.226(8), c 13.618(4) Angstrom, beta 96.51(2)degrees; R 0.072, N-o 1713.