SYNTHESIS AND CHARACTERIZATION OF 2 NEW SCHIFF-BASES AND THEIR SOLUBLE LINEAR CERIUM(IV) POLYMERS

Two new linear Ce-IV Schiff-base coordination polymers, catena-poly[cerium(IV)-mu-N,N',N'',N'''-tetrasalicylidene- 3,3',4,4'-tetraaminodiphenylmethanato-O,N,N',O',O'',N'',N''',O'''], [Ce(tstm)](n), and catena-poly[cerium(IV)-mu-N,N',N'',N'''-tetrasalicylidene-3,3',4,4'-tetraaminodiphenylsulfonato-O,N,N',O',O'',N'',N''',O''',[Ce(tsts)](n), have been successfully synthesized using step growth chelation polymerizations between cerium(IV) octoxide or tetrakis(acetylacetonato)cerium(IV) and new, premade Schiff-bases. Both new polymers exhibit excellent solubility in organic solvents with high dielectric constants, such as DMSO, NMP, and DMF. The [Ce(tstm)](n) polymer fractions with low molecular weights (<9000) also have moderate solubility in THF and dichloromethane. The molecular weights of the polymers have been characterized by end group analysis based on proton NMR, by gel permeation chromatography, and by intrinsic viscosities. The highest (M) over bar(n) values reach 28 000 for [Ce(tstm)](n) and 31 500 for [Ce(tsts)](n) after fractionation. The polymers are thermally stable to 340 degrees C and exhibit high T-g values. Mark-Houwink constants of a = 0.79 and K = 5.84 x 10(-3) cm(3)/g for [Ce(tstm)](n) and a = 0.70 and K = 1.25 x 10(-2) cm(3)/g for [Ce(tsts)](n) have been established from the intrinsic viscosities and the NMR (M) over bar(n) values. A side reaction in the condensation polymerization between tetrakis(salicylaldehydato)cerium(IV) and 3,3',4,4'-tetraaminodiphenylmethane results in some insoluble polymeric material along with some of the desired soluble polymer. [Ce(tstm)](n) provides greater solubilities and lower T-g values than either [Ce(tsts)](n) or [Ce(tsdb)](n), the analogous N,N',N'',N'''-tetrasalicylidene-3,3'-diaminobenzidine cerium polymer.