Silanol compounds, polymerizable monomers and polymers having mesogenic groups

A process for producing silanol compound having a mesogenic group, of the following formula (III):

• ##STR67## wherein each of R.sup.5 and R.sup.6 which may be the same or different, is an alkyl group or a phenyl group, X is a single bond, an oxygen atom, or a group of the formula --COO--or --OCO--, Q is a mesogenic group, and p is an integer of from 2 to 20, which comprises reacting an alkenyl compound having a mesogenic group, of the following formula (VI):
• ##STR68## wherein X and Q are as defined above, and q is an integer of from 0 to 18, and a compound of the following formula (VII):
• ##STR69## wherein R.sup.5 and R.sup.6 are as defined above, and R' is an alkyl group, in the presence of a hydrosilylation catalyst, by mixing them so that the compound of the above formula (VII) would be at least equimolar to the compound of the above formula (VI), to obtain a compound of the following formula (VIII):
• ##STR70## wherein R.sup.5, R.sup.6, R', Q and p are as defined above, and hydrolyzing the compound of the above formula (VIII) to obtain the compound of the above formula (III).