LEWIS-BASE ADDUCTS OF LEAD(II) COMPOUNDS .10. SYNTHETIC AND STRUCTURAL STUDIES OF SOME 1 1 ADDUCTS OF TET-B WITH LEAD(II) (PSEUDO-)HALIDES/

Syntheses and room-temperature single-crystal X-ray structure determin ations are recorded for 1:1 adducts of 12,14-hexamethyl-1,4,8,11-tetra azacyclotetradecane ('tet-b') with a variety of lead(II) salts. [(tet- b)PbCl2] is monoclinic, P2(1)/c, a 7.183(3), b 12.425(2), c 24.418(2) Angstrom, beta 95.32(3)degrees, Z = 4; conventional R on \F\ was 0.044 for 3188 independent, 'observed' (I > 3 sigma(I)) reflections. [(tet- b)PbI2] is monoclinic, P2(1)/c: a 19.920(5), b 7.772(5), c 15.605(6) A ngstrom, beta 108.39(2)degrees, Z = 4; R 0.051 for N-o 2507. [(tet-b)P b(NCS)(2)] is orthorhombic, P2(1)2(1)2(1), a 36.99(1), b 8.996(5), c 6 .964(3) Angstrom, Z = 4; R 0.043 for N-o 2100. All are discrete mononu clear [(tet-b)PbX(2)] entities in which the macrocyclic N-4 ligand occ upies one 'face' of the N(4)PbX(2) coordination sphere, the thiocyanat e ligands being N-bonded, with Pb-N-C angles of 116(2) and 118(1)degre es; interesting hydrogen-bonding interactions are found, columns of mo lecules being formed by way of hydrogen bonding between the coordinate d (pseudo-)halides and the NH hydrogen atoms which project to the 'rea r' face of the ligand of the next molecule, opposite the metal. In con trast to these, the bromide analogue, monoclinic, P2(1), a 9.342(3), b 12.720(5), c 18.845(5) Angstrom, beta 103.17(2)degrees, Z = 4, R 0.03 5 for N-o 3593, is best formulated as [(tet-b)PbBr] Br, one only of th e bromide entities being bound to the lead, the other being fully diss ociated by hydrogen bonding/ion pairing to the 'rear' side of adjacent ligands, forming hydrogen-bonded sheets rather than columns. This for mulation has been extended to provide a description of an analogous mi xed chloride-perchlorate 'double salt', [(tet-b)PbCl](ClO4).CH3OH, whi ch is orthorhombic, P2(1)2(1)2(1), a 19.475(2), b 18.73(1), c 6.820(2) Angstrom, Z = 4, R 0.054 for N-o 3075. However, another double salt, modelled in refinement as Pb(tet-b)Cl-0.5(ClO4)(1.5).H2O, orthorhombic Pnma, a 20.640(5), b 26.16(1), c 8.937(4) Angstrom, Z = 4 dimers, R 0 .074 for N-o 1769, is in this case more appropriately described as [(t et-b)Pb(OClO2O)(2)Pb(tet-b)] (ClO4) Cl.H2O with perchlorate rather tha n halide coordinated, and an incipiently dimeric cation, as in the par ent [(tet-b)Pb(OClO3)](2)(ClO4)(2).2H(2)O.