A new monomer 1,1-bis(4-amino-3-mercaptophenyl)-4-tert-butylcyclohexane dihydrochloride, bearing the bulky pendant 4-tert-butylcyclohexylidene group, was synthesized from 4-tert-butylcyclohexanone in three steps. Its chemical structure was characterized by H-1 NMR, C-13 NMR, MS, FTIR, and EA. Aromatic poly(bisbenzothiazole)s (PBTs V) were prepared from the new monomer and five aromatic dicarboxylic acids by direct polycondensation. The inherent viscosities were in the range of 0.63-2.17 dL/g. These polymers exhibited good solubility and thermal stability. Most of the prepared PBTs V were soluble in various polar solvents. Thermogravimetric analysis showed the decomposition temperatures at 10% weight loss that were in the range of 495-534 degrees C in nitrogen. All the PBTs V, characterized by X-ray diffraction, were amorphous. The UV absorption spectra of PBTs V showed a range of lambda(max) from 334 to 394 nm. All the PBTs V prepared had evident fluorescence emission peaks, ranging from 423 to 475 nm with different intensity. (c) 2006 Wiley Periodicals, Inc.