The present invention provides compounds as represented by structural formula (I). In formula (I), R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, and R14 are separately H or deuterium (D) independently. Moreover, at least one of R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, and R14 must be D. Also provided is use of any of the compounds or its pharmaceutical composition in the preparation of a drug for treating an anxiety.