Photoluminescent lubricating grease composition, photoluminescent material and the preparation methods thereof

A silole derivative of formula (I):

• in the formula (I), each R is independently selected from the group consisting of hydrogen, and a linear or branched C1-6 alkyl;
• each x is independently an integer between 0 and 5;
• each G is independently selected from the group consisting of hydrogen, a linear or branched C1-6 alkyl, an alkynyl of formula (I-1), an alkynyl of formula (I-2), an alkynyl of formula (I-3), an alkynyl of formula (I-4), and a group of formula (I-1′);
• in the formula (I-1), formula (I-2), formula (I-3) and formula (I-4), each R1 is independently selected from the group consisting of hydrogen, and a linear or branched C1-6 alkyl;
• each R2 is independently selected from the group consisting of a liner or branched C1-6 alkylene;
• each R is independently selected from the group consisting of hydrogen, and a linear or branched C1-6 alkyl;
• each x is independently an integer between 0-5;
• each y is independently an integer between 0-4;
• and each z is independently an integer between 1 and 4;
• in the formula (I-1), one of A and A′ is NR, and the other is S, wherein R is selected from the group consisting of hydrogen, and a linear or branched C1-6 alkyl;
• in the formula (I), formula (I-2) and formula (I-3), each G′ is independently selected from the group consisting of hydrogen, a linear or branched C1-6 alkyl, a group of formula (I-1′), an alkynyl of formula (I-2′), and an alkynyl of formula (I-3′);
• in the formula (I-1′) and formula (I-2′), each R is independently selected from the group consisting of hydrogen, and a linear or branched C1-6 alkyl;
• each x is independently an integer between 0-5;
• each y′ is independently an integer between 0-3;
• each z′ is independently an integer between 0-3;
• in the formula (I-3′), R4 is a group of formula (II-1), R3 and R5 are hydrogen;
• or R3 and R5 are a group of formula (II-3), R4 is hydrogen;
• in the formula (II-1), R6 is hydrogen, or a linear or branched C1-6 hydrocarbyl;
• in the formula (II-3), Ra is selected from the group consisting of hydrogen, and a linear or branched C1-20 alkyl;
• Rb is selected from the group consisting of hydrogen, and a linear or branched C1-20 alkyl;
• and
• in the formula (I), at least one G is selected from the group consisting of an alkynyl group of formula (I-1), an alkynyl group of formula (I-2), an alkynyl group of formula (I-3), and an alkynyl group of formula (I-4), or at least one G′ is selected from the group consisting of an alkynyl group of formula (I-2′), and an alkynyl group of formula (I-3′).