Thio(di)silanes

A thiodisilane of formula (I-a):

• (R1aR1bR1cCS)s(Si—Si)Hh (I-a),
• wherein:
• subscript s is an integer from 1 to 6;
• subscript h is an integer from 0 to 5;
• with the proviso that sum s+h=6
• each H, when present in formula (I), is independently bonded to the same or different one of the silicon atoms in formula (I);
• wherein R1a, R1b, and R1c are defined by limitation (a), (b), or (c):
• (a) at least one R1a independently is (C1-C20)alkyl or phenyl and each of any remaining R1a, R1b, and R1c independently is H or (C1-C20)hydrocarbyl;
• or
• (b) at least one R1aR1bR1cC group is independently a (C6-C20)aryl that is unsubstituted or substituted with substituent SUB and each of R1a, R1b, and R1c of remaining R1aR1bR1cC groups independently is H or (C1-C20)hydrocarbyl, with the proviso that when subscript s is 2, the remaining R1aR1bR1cC group is a (C6-C20)aryl that is substituted with substituent SUB, or R1a, R1b, and R1c of the remaining R1aR1bR1cC group independently is H or (C1-C20)hydrocarbyl;
• or
• (c) any two of R1a, R1b, and R1c in the same or different R1aR1bR1cC group are bonded together to form a divalent group, —R11—, wherein —R11— is a CH2 or a (C3-C20)hydrocarbylene and each of any remaining R1a, R1b, and R1c independently is H or (C1-C20)hydrocarbyl;
• each hydrocarbyl and hydrocarbylene independently is unsubstituted or substituted with from 1 to 5 substituents SUB;
• and
• each SUB independently is unsubstituted (C1-C6)alkyl, unsubstituted (C3-C6)cycloalkyl, unsubstituted (C2-C6)alkenyl, unsubstituted (C2-C6)alkynyl, unsubstituted (C6-C7)aryl, fluoro, chloro, or bromo.