Stabilized semiconductor nanocrystals

A polydentate ligand of formula:

• wherein n is 1, 2 or 3, m is 1, 2, 3,4, or 5, each k is 1 or 2, each X independently is a donor group selected from the group consisting of N, P, P═O, and N═O, each Y is substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryl, or substituted or unsubstituted aryloxy, and L is a linking group optionally terminated by O and includes at least one carbonate, carbamate, amide, ester or ether linkage.

A distribution of polydentate ligands of formula:

• wherein n is 1, 2 or 3, m is 1, 2, 3, 4, or 5, each k is 1 or 2, each X independently is a donor group selected from the group consisting of N, P, P═O, and N═O, each Y is substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryl, or substituted or unsubstituted aryloxy, L is a linking group optionally terminated by O and includes at least one carbonate, carbamate, amide, ester or ether linkage, and the distribution includes at least two members with different values of m.

A polydentate ligand of formula:

• wherein p is 1 or 2, each m is 1, 2, 3, 4, or 5, each k is 1 or 2, each j is 0 or 1, each p is 0 or 1, q is 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, each X independently is a donor group selected from the group consisting of N, P, P═O, and N═O, each Y is substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryl, or substituted or unsubstituted aryloxy, and L is a linking group optionally terminated by O and includes at least one carbonate, carbamate, amide, ester or ether linkage.

A polydentate ligand of formula:

• wherein n is 1, 2 or 3, m is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, each k is 1 or 2, each x independently is 0 or 1, each of Z1 and Z2, independently, is an ether, amide, ester, carbamate or carbonate linkage, each R1 and R2, independently, is an alkylene optionally interrupted by S, O, NH, N-lower alkyl, arylene, heteroarylene, or aralkylene and optionally terminated by S, O, NH, N-lower alkyl, arylene, heteroarylene, or aralkylene, and each R is substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, or substituted or unsubstituted aryl.

A polydentate ligand of formula:

• wherein n is 1, 2 or 3, m is 1, 2, 3, 4, or 5, each k is 1 or 2, each x independently is 0 or 1, Z is an ether, carbamate, amide, ester or carbonate linkage, each R1 and each R2, independently, is an alkylene optionally interrupted by S, O, NH, N-lower alkyl, arylene, heteroarylene, or aralkylene, and optionally terminated by S, O, NH, N-lower alkyl, arylene, heteroarylene, or aralkylene, and each R is substituted or unsubstituted alkyl, or substituted or unsubstituted aryl, and each R is bonded to R1 via an ether, ester, amide, carbamate or carbonate linkage.

A polydentate ligand of formula:

• wherein n is 1, 2 or 3, m is 1, 2, 3, 4, or 5, each k is 1 or 2, each x independently is 0 or 1, and each R is substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, or substituted or unsubstituted aryl.

A method of making a polydentate ligand comprising contacting a monomeric, polyfunctional phosphine with a polyfunctional oligomerization reagent to form an oligomeric phosphine.

A method of making a nanocrystal-biomolecule conjugate comprising contacting a nanocrystal including a polydentate ligand including a reactive group with a biomolecule.