The invention relates to the field of
liquid crystal materials, in particular to 7,8-difluoro-5-methyl-1,2,3,4-tetrahydronaphthalene
liquid crystal compounds. The compounds have a structure represented as a general formula I, wherein R represents
alkyl or alkoxy with 1-12 carbon atoms; a ring A represents 1,4-
phenylene, 1,4-cyclohexylidene or 1,4-
phenylene with
fluorine atoms substituting 1-4
hydrogen atoms; a ring B represents 1,4-
phenylene, 1,4-cyclohexylidene, 1,4-cyclohexenylene or 1,4-phenylene with
fluorine atoms substituting 1-4
hydrogen atoms; m is 0, 1 or 2. The
liquid crystal compounds have the advantages of higher negative
dielectric anisotropy, good liquid
crystal intersolubility, relatively low rotary
viscosity and the like which are needed for improvement of the
crystal liquid materials, and the liquid
crystal compounds have great application value.