Lewis-Base Adducts of Lead(II) Compounds. XIX. Synthetic and Structural Studies of Some 1:1 Adducts of 2,4,6-Tris (2-pyridyl)-1,3,5-triazine With Lead(II) (Pseudo-)Halides

Abstract

Syntheses and room-temperature single-crystal X-ray structure determinations are recorded for 1:1 adducts of 2,4,6-tris(2-pyridyl) 1,3,5-triazine (' trz ') with lead(II) chloride, bromide, iodide and thiocyanate, the chloride and bromide being methanol monosolvates. [( trz )PbCl2](8|8). MeOH is monoclinic, P 2/c, a 9.178(2), b 14.833(3), c 7.347(8) ?, ß 93.89(2)°, Z = 2 f.u .; R was 0.042 for No = 1451 'observed' (I > 3s(I)) reflections; the bromide is related, having a derivative triclinic cell, Pi, a 9.259(3), b 15.153(6), c 7.428(2) ?, a 90.28(3), ß 94.62(2), ? 91.15(3)°, Z = 2 f.u .; R was 0.047 for No 2729. [( trz )PbI2](8|8), also solvated, is triclinic, Pi , a 15.266(9), b 8.9448(8), c 8.148(11) ?, a 80.60(6), ß 77.05(7), ? 83.45(3)°, Z = 2; R was 0.032 for No 3222. In all three compounds an infinite PbX2PbX2Pb polymer is found with the plane of the tridentate trz lying quasi normal to the polymer axis. Pb -N distances lie between 2.63(1) and 2.803(8) ?; Pb-Cl are 2.848(3) and 3.074(3), Pb -Br 2.963(2)-3.257(2) and Pb-I 3.192(3)-3.466(2) ?. The thiocyanate, monoclinic, C 2/c, a 16.974(6), b 6.410(2), c 39.49(2) ?, ß 96.33(4)°, Z = 8, R 0.13 for No 2465, is a column of dimeric units stacked up b, successive lead atoms being bridged by thiocyanate sulfur atoms packed in between them, and quasi-parallel to a, and by thiocyanates parallel to b which link pairs of lead atoms in each dimer with the same b coordinate by pairs of bridging nitrogens and bridging sulfurs from the adjacent pair.