The in-vitro use of a compound that has the structure below in the preparation of: a covalent conjugate between the compound and an attached carrier molecule which is a peptide, a nucleic acid, a protein, an antibody, a receptor, an enzyme, a drug, or is a pesticide; or a covalent conjugate between the compound and a support which is controlled pore glass, glass plates, polystyrene, avidin coated polystyrene beads, acrylamide gel or activated dextran; the structure of the compound being a member selected from: and wherein, X 5 and X 6 are members independently selected from H, substituted or unsubstituted C 1 -C 6 alkyl, -OR', -COOR', -NR'R", -SH, -OP(OX 3)N(X 4) 2, wherein R' and R" are members independently selected from the group consisting of H, and alkyl or substituted alkyl and wherein X 3 and X 4 are members independently selected from CN, and substituted or unsubstituted C 1 -C 6 alkyl; wherein at least one of X 5 and X 6 is a reactive group that has the formula: wherein R 9 and R 10 are members independently selected from substituted and unsubstituted alkyl; X 1 and X 2 are members independently selected from -OH, -COOH, -NH 2, -SH, and -P(OX 3)N(X 4) 2; and wherein X 3 and X 4 are members independently selected from substituted and unsubstituted alkyl. a covalent conjugate between the compound and an attached carrier molecule which is a peptide, a nucleic acid, a protein, an antibody, a receptor, an enzyme, a drug, or is a pesticide; or a covalent conjugate between the compound and a support which is controlled pore glass, glass plates, polystyrene, avidin coated polystyrene beads, acrylamide gel or activated dextran; the structure of the compound being a member selected from: and wherein, X 5 and X 6 are members independently selected from H, substituted or unsubstituted C 1 -C 6 alkyl, -OR', -COOR', -NR'R", -SH, -OP(OX 3)N(X 4) 2, wherein R' and R" are members independently selected from the group consisting of H, and alkyl or substituted alkyl and wherein X 3 and X 4 are members independently selected from CN, and substituted or unsubstituted C 1 -C 6 alkyl; wherein at least one of X 5 and X 6 is a reactive group that has the formula: wherein R 9 and R 10 are members independently selected from substituted and unsubstituted alkyl; X 1 and X 2 are members independently selected from -OH, -COOH, -NH 2, -SH, and -P(OX 3)N(X 4) 2; and wherein X 3 and X 4 are members independently selected from substituted and unsubstituted alkyl. X 5 and X 6 are members independently selected from H, substituted or unsubstituted C 1 -C 6 alkyl, -OR', -COOR', -NR'R", -SH, -OP(OX 3)N(X 4) 2, wherein R' and R" are members independently selected from the group consisting of H, and alkyl or substituted alkyl and wherein X 3 and X 4 are members independently selected from CN, and substituted or unsubstituted C 1 -C 6 alkyl; wherein at least one of X 5 and X 6 is a reactive group that has the formula: wherein R 9 and R 10 are members independently selected from substituted and unsubstituted alkyl; X 1 and X 2 are members independently selected from -OH, -COOH, -NH 2, -SH, and -P(OX 3)N(X 4) 2; and wherein X 3 and X 4 are members independently selected from substituted and unsubstituted alkyl.