Patent ID: 7956141

Claim:
A complex comprising a mono-anionic tridentate ligand, represented by the following general formula (I): wherein in the general formula (I), M represents scandium Sc, yttrium Y, or lanthanoid; E 1 -T 1 -X-T 2 -E 2 represents a mono-anionic tridentate ligand; X represents an anionic electron-donating group containing a ligand atom selected from Group-15 atoms; E 1 and E 2 each represent independently a neutral electron-donating group containing a ligand atom selected from one of Group-15 atoms and Group-16 atoms; T 1 and T 2 are cross-linking groups that cross-link X with E 1 and E 2 , and each represent independently an arylene group which may have a substituent on an aryl ring; Q 1 and Q 2 each represent independently a monoanionic ligand; L represents a neutral Lewis base; and w represents an integral of 0 to 3.