Liquid crystal compound and liquid crystal composition

A liquid crystal compound represented by formula I,

• wherein R1 represents an alkyl group having a carbon atom number of 1-10, a fluoro-substituted alkyl group having a carbon atom number of 1-10, an alkoxy group having a carbon atom number of 1-10, a fluoro-substituted alkoxy group having a carbon atom number of 1-10, an alkenyl group having a carbon atom number of 2-10, a fluoro-substituted alkenyl group having a carbon atom number of 2-10, an alkenoxy group having a carbon atom number of 3-8 or a fluoro-substituted alkenoxy group having a carbon atom number of 3-8, and any one or more non-connected CH2 in the groups represented by R1 may be substituted with cyclopentyl, cyclobutyl, cyclopropyl or —O—;
• each
• independently represents
• or fluorobenzene;
• where n represents 2 or 3, not every
• represents
• Z0 represents CF2O, CH2O, COO or a single bond;
• and,
• the dielectric anisotropy of the liquid crystal compound is positive.