Chemotherapeutic agents : 9 : synthesis and pesticidal activities of bis[4-aryl-alkyl-1,2,4-triazoline-5-thione-3-yl]alkanes and 1-aryl-alkyl-3-[4-(4-aryl-alkyl-1,2,4-triazoline-5-thione-3-yl)phenyl]th iourea