STRUCTURAL ASPECTS OF LITHIUM ARENETHIOLATE COMPLEXES WITH INTRAMOLECULAR COORDINATING AMINE DONORS

Reaction of aryllithium reagents LiR (R = C6H4((R)-CH(Me)NMe(2))-2 (1a ), C6H3(CH(2)NMe(2))(2)-2,6 (1b), C6H4(CH2N(Me)CH(2)CH(2)OMe)-2 (1c)) with 1 equiv of sulfur (1/8 S-8) results in the quantitative formation of the corresponding lithium arenethiolates [Li{SC6H4((R)-CH(Me)NMe(2 ))-2)}](6) (3), [Li{SC6H3(CH(2)NMe(2))(2)-2,6}](6) (4), and [Li{SC6H4( CH2N(Me)CH(2)CH(2)OMe)-2)}](2) (5). Alternatively, 3 can be prepared b y reacting the corresponding arenethiol HSC6H4((R)-CH(Me)NMe(2))-2 (2) with (n)BuLi. X-ray crystal structures of lithium arenethiolates 3 an d 4, reported in abbreviated form, show them to have hexanuclear prism atic and hexanuclear planar structures, respectively, that are unprece dented in lithium thiolate chemistry. The lithium arenethiolate [Li{SC 6H4(CH2N(Me)CH2-CH(2)OMe)-2}](2) (5) is dimeric in the solid state and in solution, and crystals of 5 are monoclinic, space group P2(1)/c, w ith a = 17.7963(9) Angstrom, b = 8.1281(7) Angstrom, c = 17.1340(10) A ngstrom, beta = 108.288(5)degrees, Z = 4, and final R = 0.047 for 4051 reflections with F > 4 sigma(F). Hexameric 4 reacts with 1 equiv of l ithium iodide and 2 equiv of tetrahydrofuran to form the dinuclear add uct [Li-2(SAr)(I)(THF)(2)] (6). Crystals of 6 are monoclinic, space gr oup P2(1)/c, with a = 13.0346(10) Angstrom, b = 11.523(3) Angstrom, c = 16.127(3) Angstrom, beta = 94.682(10)degrees, Z = 4, and final R = 0 .059 for 3190 reflections with F > 4 sigma(F).