“…1). 33 Whereas [CrL x (CN) (6-2x) ] (3-2x)− (L = neutral didentate ligand, for example, 1,10-phenanthorline ( phen) or 2,2′ bipyridine (bipy)) or [CrL(CN) 3 ] (L = neutral facial tridentate ligand, for example, 1,4,7-triazacyclononane (tacn)) building blocks have been developed extensively for the design of magnetic clusters and assemblies, [2][3][4]14,19 their use as potential optical partners remained confidential. We are aware of one contribution exploring the systematic low-energy shift of the Cr( 2 T 1 , 2 E → 51 On the other side, the recent need for replacing the costly and rarest 4d (Ru) and 5d (Re, Os, Ir) metals with earth abundant 3d (Cr), 27,28,35,52,54 Mn (I) 52,54 or 4d (Mo) 55 analogues boosted the use of the rigid tridentate polyaromatic ligands 2,2′:6′,2″-terpyridine (tpy), N,N′dimethyl-N,N′-di( pyridine-2-yl)pyridine-2,6-diamine (ddpd) or 2,6-di(quinolin-8-yl)pyridine (dqp) ligands for tuning ligand-field and Racah parameters via chelate ring sizes, donor atoms and sterical constraints around Cr III in pseudo-octahedral homoleptic [CrL 2 ] 3+ (L = tpy, ddpd or dqp; Scheme 1a) [56][57][58] and heteroleptic [Cr(L)(L′)] 3+ complexes.…”