sented by the formula (I) wherein R3 and R4 are C1-C4 alkyl groups; a fluorine-containing organosulfur compound represented by the formula (I) wherein R3 is a C1-C4 alkyl group and R4 is a hydrogen atom; a fluorine-containing organosulfur compound represented by the formula (I) wherein R3 is a methyl group and R4 is a hydrogen atom; a fluorine-containing organosulfur compound represented by the fo