Controlled release composition

A disulfide of formula (5):

• J—S—S—L—Q1—T—Q2—M—G—Z (5),
• wherein —L— is —(ALj—BLk—ELl—DL)m—;
• each AL, BL, EL and DL are individually C(RLARLA′)—, —C(RLBRLB′)—, —C(RLERLE′)—, and —C(RLDRLD′)—, respectively;
• each RLA, RLB, RLE and RLD are individually H, or any two of RLA, RLB, RLE and RLD together form a bond, or RLA, RLB, RLE and RLD together with the atoms to which they are bonded form a six-membered aromatic ring;
• each RLA′, RLB′, RLE′ and RLD′ are individually H, or any two of RLA′, RLB′, RLE′ and RLD′ together form a bond, or RLA′, RLB′, RLE′ and RLD′ together with the atoms to which they are bonded form a six-membered aromatic ring;
• each j, k and l are individually either 0 or 1;
• m is 1 to 5;
• —Q1— and —Q2— are each individually selected from the group consisting of
• 23
• —T— is a moiety of formula (2) or formula (3)
• 24
• R1 and R2 are each individually selected from the group consisting of H and OH;
• a is 0 to 3;
• b is0 to 3;
• indicates that the chirality of the carbon atom to which it is attached may be either R or S;
• n is 1 to 6;
• —M— is —(Ax—By—Ez—D)w—;
• A is —O—, —S—, —N(RA)— or —C(RARA′)—;
• B is —O—, —S—, —N(RB)— or —C(RBRB′)—;
• E is —O—, —S—, —N(RE)— or —C(RERE′)—;
• D is —C(RDRD′)—;
• each RA, RB, RE and RD is selected from the group consisting of H, alkyl, alkenyl, alkynyl, aryl and heterocyclic radical, or any two of RA, RB, RE and RD together form a bond, or any two of RA, RB, RE and RD together with the atoms to which they are bonded for a ring;
• each RA′, RB′, RE′ and RD′ is selected from the group consisting of H, alkyl, alkenyl, alkynyl, aryl and heterocyclic radical, or any two of RA′, RB′, RE′ and RD′ together form a bond, or any two RA′, RB′, RE′ and RD′ together with the atoms to which they are bonded for a ring;
• each x, y and z is either 0 or 1;
• —G— is a moiety of formula (4)
• 25
• R3, R4, and R5 are each individually a —CH2— group substituted with a hydrogen or an alkyl group;
• R6 is a hydrogen, alkyl, alkenyl, alkynyl, aryl, halogen, heterocyclic radical or nitro group;
• X is a bond or —(AXp—BXq—EXr—DX)s—;
• each AX, BX, EX and DX is individually C(RXARXA′)—, —C(RXBRXB′)—, —C(RXERXE′)—, or —C(RXDRXD′)—, respectively;
• each RXA, RXB, RXE and RXD is individually H, or any two of RXA, RXB, RXE and RXD together form a bond, or RXA, RXB, RXE and RXD together with the atoms to which they are bonded form a six-membered aromatic ring;
• each RXA′, RXB′, RXE′ and RXD′ is individually H, or any two of RXA′, RXB′, RXE′ and RXD′ together form a bond, or RXA′, RXB′, RXE′ and RXD′ together with the atoms to which they are bonded form a six-membered aromatic ring;
• each p, q and r is individually either 0 or 1;
• s is I to 5;
• Y is —O— or —NH—;
• R7 and R8 are both single bonds, or together with the atoms to which they are bonded from one or more fused rings, substituted or unsubstituted, optionally containing heteroatoms;
• —Z is a leaving group
• —J is selected from the group consisting of H, halogen, R, —OR, —NRR′, —C(O)R, and —C(O)OR;
• R is selected from the group consisting of alkyl, alkenyl, alkynyl, aryl and heterocyclic radical;
• and
• R′ is selected from the group consisting of H, alkyl, alkenyl, alkynyl, aryl and heterocyclic radical.

A substrate, comprising:

• (i) a surface layer comprising gold, and
• (ii) a plurality of moieties, on at least a portion of said surface layer,
• wherein said moieties are alkanethiolate moieties of formula (8):
• Surf—S—L—Q1—T—Q2—M—G—Z (8)
• wherein —L— is —(ALj—BLk—ELl—DL)m—;
• each AL, BL, EL and DL are individually —C(RLARLA′)—, C(RLBRLB′)—, —C(RLERLE′)—, and —C(RLDRLD′)—, respectively;
• each RLA, RLB, RLE and RLD are individually H, or any two of RLA, RLB, RLE and RLD together form a bond, or RLA, RLB, RLE and RLD together with the atoms to which they are bonded form a six-membered aromatic ring;
• each RLA′, RLB′, RLE′ and RLD′ are individually H, or any two of RLA′, RLB′, RLE′ and RLD′ together form a bond, or RLA′, RLB′, RLE′ and RLD′ together with the atoms to which they are bonded form a six-membered aromatic ring;
• each j, k and l are individually either 0 or 1;
• m is 1 to 5;
• —Q1— and —Q2— are each individually selected from the group consisting of
• 28
• —T— is a moiety of formula (2) or formula (3)
• 29
• R1 and R2 are each individually selected from the group consisting of H and OH;
• a is 0 to 3;
• b is 0 to 3;
• indicates that the chirality of the carbon atom to which it is attached may be either R or S;
• n is 1 to 6;
• —M— is —(Ax—By—Ez—D)w—;
• A is —O—, —S—, —N(RA)— or —C(RARA′)—;
• B is —O—, —S—, —N(RB)— or —C(RBRB′)—;
• E is —O—, —S—, —N(RE)— or —C(RERE′)—;
• D is —C(RDRD′)—;
• each RA, RB, RE and RD is selected from the group consisting of H, alkyl, alkenyl, alkynyl, aryl and heterocyclic radical, or any two of RA, RB, RE and RD together form a bond, or any two of RA, RB, RE and RD together with the atoms to which they are bonded for a ring;
• each RA′, RB′, RE′ and RD′ is selected from the group consisting of H, alkyl, alkenyl, alkynyl, aryl and heterocyclic radical, or any two of RA′, RB′, RE′ and RD′ together form a bond, or any two RA′, RB′, RE′ and RD′ together with the atoms to which they are bonded for a ring;
• each x, y and z is either 0 or 1;
• —G— is a moiety of formula (4)
• 30
• R3, R4, and R5 are each individually a —CH2— group substituted with a hydrogen or an alkyl group;
• R6 is a hydrogen, alkyl, alkenyl, alkynyl, aryl, halogen, heterocyclic radical or nitro group;
• X is a bond or —(AXp—BXq—EXr—DX)s—;
• each AX, BX, EX and DX is individually C(RXARXA′)—, —C(RXBRXB′)—, —C(RXERXE′)—, or —C(RXDRXD′)—, respectively;
• each RxA, RXB, RXE and RXD is individually H, or any two of RXA, RXB, RXE and RXD together form a bond, or RXA, RXB, RXE and RXD together with the atoms to which they are bonded form a six-membered aromatic ring;
• each RXA′, RXB′, RXE′ and RXD′ is individually H, or any two of RXA′, RXB′, RXE′ and RXD′ together form a bond, or RXA′, RXB′, RXE′ and RXD′ together with the atoms to which they are bonded form a six-membered aromatic ring;
• each p, q and r is individually either 0 or 1;
• s is 1 to 5;
• Y is —O— or —NH—;
• R7 and R8 are both single bonds, or together with the atoms to which they are bonded from one or more fused rings, substituted or unsubstituted, optionally containing heteroatoms;
• —Z is a leaving group;
• and
• Surf designates where the moiety attaches to said surface.