Hole transport compositions and related devices and methods (I)

A composition comprising:

• at least one first compound and at least one second compound different from the first,
• wherein the at least one first compound comprises a hole transporting core which is a fluorene core or a biphenyl core, wherein the hole transporting core is covalently bonded to a first arylamine group and also covalently bonded to a second arylamine group, and wherein the core is further covalently bonded to at least two solubilizing groups comprising at least four carbon atoms, and wherein the solubilizing groups are optionally substituted with intractability groups;
• wherein the at least one second compound comprises a hole transporting core which is a fluorene core or a biphenyl core, wherein the hole transporting core is covalently bonded to a first arylamine group and also covalently bonded to a second arylamine group, wherein the second compound further comprises at least one intractability group which may be bonded to the first arylamine group, the second arylamine group, or both;
• wherein the first and second compounds have molecular weight of about 5,000 g/mole or less,
• wherein for the first compound, the solubilizing group of the core is unsubstituted with intractability group,
• wherein the first compound does not comprise intractability groups bonded to the core.

A composition comprising:

• at least one first compound and at least one second compound different from the first,
• wherein the at least one first compound comprises a hole transporting core which is a fluorene core or a biphenyl core, wherein the hole transporting core is covalently bonded to a first arylamine group and also covalently bonded to a second arylamine group, and wherein the core is further covalently bonded to at least two solubilizing groups comprising at least four carbon atoms, and wherein the solubilizing groups are optionally substituted with intractability groups;
• wherein the at least one second compound comprises a hole transporting core which is a fluorene core or a biphenyl core, wherein the hole transporting core is covalently bonded to a first arylamine group and also covalently bonded to a second arylamine group, wherein the second compound further comprises at least one intractability group which may be bonded to the first arylamine group, the second arylamine group, or both;
• wherein the first and second compounds have molecular weight of about 5,000 g/mole or less,
• wherein for the first compound, the solublizing group is substituted with the intractability group and the for the second compound, the core does not comprise at least two solublizing groups comprising at least four carbon atoms, and
• wherein the first compound is represented by:

A composition comprising:

• at least one compound comprising a hole transporting core which is a fluorene core, wherein the core is covalently bonded to a first arylamine group and also covalently bonded to a second arylamine group, and wherein the compound is covalently bonded to at least one intractability group, and wherein the compound has a molecular weight of about 5,000 g/mole or less, wherein the intractability group is covalently bonded to the hole transport core but not the first arylamine group or the second arylamine group, and wherein each of the first and second arylamine groups are independently represented by —N(R1)(R2), and
• wherein at least one of R1 and R2 is an optionally substituted biphenyl group, or
• wherein at least one of R1 and R2 is an optionally substituted carbazole group, or
• wherein —N(R1)(R2) form an optionally substituted carbazole group, or
• wherein at least one of R1 and R2 is an optionally substituted naphthyl group, or
• wherein at least one of R1 and R2 is an optionally substituted thienobenzene group, or
• wherein at least one of R1 and R2 is an optionally substituted fluorene group, or
• wherein at least one of R1 and R2 is an optionally substituted group comprising at least two fused aromatic rings.