A catalyst system comprising a metal-ligand complex according to formula: where M is a metal chosen from titanium, zirconium, or hafnium, the metal having a formal oxidation state of +2, +3, or +4; each X is a monodentate or bidentate ligand independently chosen from unsaturated (C 2 -C 50)hydrocarbon, unsaturated (C 2 -C 50)heterohydrocarbon, (C 1 -C 50)hydrocarbyl, (C 6 -C 50)aryl, (C 6 -C 50)heteroaryl, cyclopentadienyl, substituted cyclopentadienyl, (C 4 -C 12)diene, halogen, -N(R N) 2, and -NCOR C; n is 1, 2, or 3; m is 1 or 2; the metal-ligand complex has 6 or fewer metal-ligand bonds; each Y is independently selected from oxygen or sulfur; each R 1 is independently selected from the group consisting of (C 1 -C 50)hydrocarbyl, (C 1 -C 50)heterohydrocarbyl, (C 6 -C 50)aryl, (C 4 -C 50)heteroaryl, -Si(R C) 3, -Ge(R C) 3, -P(R P) 2, -N(R N) 2, -OR C, -SR C, -NO 2, -CN, -CF 3, R C S -, -P (R P) 2, R C S 2 -, (R C) 2 C=N-, R C C O-, R C OC -, R C C N -, (R C) 2 NC -, halogen, and -H; each R 2 is independently chosen from (C 1 -C 50)hydrocarbyl, (C 1 -C 50)heterohydrocarbyl, (C 6 -C 50)aryl, (C 4 -C 50)heteroaryl, -Si(R C) 3, and -Ge(R C) 3; for each individual ring containing groups z 1 and z 2, each of z 1 and z 2 is independently selected from the group consisting of sulfur, oxygen, -N(R R)-, =N-, and -C(R R)-, provided that at least one of z 1 or z 2 is -C(R R)-; each A is independently chosen from -z 3 -z 4- z 5 - or -C(R 3)C(R 4)C(R 5)C(R 6)-, where: each of z 3, z 4, and z 5 is selected from the group consisting of sulfur, oxygen, -N(R R)-, and -C(R R)-, provided that exactly one of z 3, z 4, or z 5 is -C(R R)- or that exactly two of z 3, z 4, or z 5 are -C(R R)-; and each R 3, R 4, R 5, and R 6 is independently chosen from (C 1 -C 50)hydrocarbyl, (C 1 -C 50)heterohydrocarbyl, (C 6 -C 50)aryl, (C 4 -C 50)heteroaryl, -Si(R C) 3, -Ge(R C) 3, -P(R P) 2, -N(R N) 2, -OR C, -SR C, -NO 2, -CN, -CF 3, R C S -, R C S 2 -, (R C) 2 C=N-, R C C O-, R C OC -, R C C N -, (R C) 2 NC -, halogen, or -H; each R C, R N, and R P in formula is independently a (C 1 -C 50)hydrocarbyl; and each R R is independently chosen from (C 1 -C 50)hydrocarbyl, (C 1 -C 50)heterohydrocarbyl, (C 6 -C 50)aryl, (C 4 -C 50)heteroaryl, -Si(R C) 3, -Ge(R C) 3, -P(R P) 2, -N(R N) 2, -OR C, -SR C, -NO 2, -CN, -CF 3, R C S -, R C S 2 -, (R C) 2 C=N-, R C C O-, R C OC -, R C C N -, (R C) 2 NC -, halogen, or -H, wherein any two R R groups bonded to neighboring atoms are optionally linked. M is a metal chosen from titanium, zirconium, or hafnium, the metal having a formal oxidation state of +2, +3, or +4; each X is a monodentate or bidentate ligand independently chosen from unsaturated (C 2 -C 50)hydrocarbon, unsaturated (C 2 -C 50)heterohydrocarbon, (C 1 -C 50)hydrocarbyl, (C 6 -C 50)aryl, (C 6 -C 50)heteroaryl, cyclopentadienyl, substituted cyclopentadienyl, (C 4 -C 12)diene, halogen, -N(R N) 2, and -NCOR C; n is 1, 2, or 3; m is 1 or 2; the metal-ligand complex has 6 or fewer metal-ligand bonds; each Y is independently selected from oxygen or sulfur; each R 1 is independently selected from the group consisting of (C 1 -C 50)hydrocarbyl, (C 1 -C 50)heterohydrocarbyl, (C 6 -C 50)aryl, (C 4 -C 50)heteroaryl, -Si(R C) 3, -Ge(R C) 3, -P(R P) 2, -N(R N) 2, -OR C, -SR C, -NO 2, -CN, -CF 3, R C S -, -P (R P) 2, R C S 2 -, (R C) 2 C=N-, R C C O-, R C OC -, R C C N -, (R C) 2 NC -, halogen, and -H; each R 2 is independently chosen from (C 1 -C 50)hydrocarbyl, (C 1 -C 50)heterohydrocarbyl, (C 6 -C 50)aryl, (C 4 -C 50)heteroaryl, -Si(R C) 3, and -Ge(R C) 3; for each individual ring containing groups z 1 and z 2, each of z 1 and z 2 is independently selected from the group consisting of sulfur, oxygen, -N(R R)-, =N-, and -C(R R)-, provided that at least one of z 1 or z 2 is -C(R R)-; each A is independently chosen from -z 3 -z 4- z 5 - or -C(R 3)C(R 4)C(R 5)C(R 6)-, where: each of z 3, z 4, and z 5 is selected from the group consisting of sulfur, oxygen, -N(R R)-, and -C(R R)-, provided that exactly one of z 3, z 4, or z 5 is -C(R R)- or that exactly two of z 3, z 4, or z 5 are -C(R R)-; and each R 3, R 4, R 5, and R 6 is independently chosen from (C 1 -C 50)hydrocarbyl, (C 1 -C 50)heterohydrocarbyl, (C 6 -C 50)aryl, (C 4 -C 50)heteroaryl, -Si(R C) 3, -Ge(R C) 3, -P(R P) 2, -N(R N) 2, -OR C, -SR C, -NO 2, -CN, -CF 3, R C S -, R C S 2 -, (R C) 2 C=N-, R C C O-, R C OC -, R C C N -, (R C) 2 NC -, halogen, or -H; each of z 3, z 4, and z 5 is selected from the group consisting of sulfur, oxygen, -N(R R)-, and -C(R R)-, provided that exactly one of z 3, z 4, or z 5 is -C(R R)- or that exactly two of z 3, z 4, or z 5 are -C(R R)-; and each R 3, R 4, R 5, and R 6 is independently chosen from (C 1 -C 50)hydrocarbyl, (C 1 -C 50)heterohydrocarbyl, (C 6 -C 50)aryl, (C 4 -C 50)heteroaryl, -Si(R C) 3, -Ge(R C) 3, -P(R P) 2, -N(R N) 2, -OR C, -SR C, -NO 2, -CN, -CF 3, R C S -, R C S 2 -, (R C) 2 C=N-, R C C O-, R C OC -, R C C N -, (R C) 2 NC -, halogen, or -H; each R C, R N, and R P in formula is independently a (C 1 -C 50)hydrocarbyl; and each R R is independently chosen from (C 1 -C 50)hydrocarbyl, (C 1 -C 50)heterohydrocarbyl, (C 6 -C 50)aryl, (C 4 -C 50)heteroaryl, -Si(R C) 3, -Ge(R C) 3, -P(R P) 2, -N(R N) 2, -OR C, -SR C, -NO 2, -CN, -CF 3, R C S -, R C S 2 -, (R C) 2 C=N-, R C C O-, R C OC -, R C C N -, (R C) 2 NC -, halogen, or -H, wherein any two R R groups bonded to neighboring atoms are optionally linked.