Spontaneous Resolution of Racemic Salen-Type Ligand in the Construction of 3D Homochiral Lanthanide Frameworks

Abstract

A series of three 3D homochiral lanthanide− organic frameworks {[Ln(H 2 L SS )(NO 3 ) 2 Cl]•2CH 2 Cl 2 } n [Ln = La (1), Ce (2), and Nd (3)] with the unique diamond (dia) topology have been obtained by utilizing racemic salen-type ligand and mixed lanthanide salts. Complexes 1−3 are isostructural, crystallizing in the chiral tetragonal space group P4 3 2 1 2 and adopting an individual dia network formed by lanthanide ions and bridging ligand trans-N,N′-bis-(salicylidene)-(1S,2S)-cyclohexanediamine (H 2 L SS ). This "from racemate to homochiral" approach may point to a new avenue for the preparation of homochiral materials.

OAc–-Dependent Self-Assembly of Luminescent Homoleptic [Ln9(OH-Salen)5(OH)4(OAc)10] and {[Ln6(OH-MeO-Salen)5(OH)(OAc)2(H2O)2]·(OAc)} Complexes

“…As a matter of fact, for the typical compartmental Salen-type Schiff-base ligands, NO 3 – - or Cl – -dependent mononuclear ([Ln­(H 2 Salen)­(NO 3 ) 3 ]), dinuclear ([Ln­(H 2 Salen) 2 ­(NO 3 ) 3 ] 2 or {[Ln­(H 2 Salen) 2 Cl 2 ] 2 ­·2Cl}) to 1D ({Ln­(H 2 Salen) 2 ­(NO 3 ) 3 } n ), 2D ([Ln­(H 2 Salen) 1.5 ­(NO 3 ) 3 ] n ), or 3D ([Ln­(H 2 Salen)­(NO 3 ) 2 Cl] n ) polymeric complexes are obtained, in which the discrete-to-polymeric structures are mainly based on the flexible H 2 Salen ligand with two μ-O-phenoxide atoms chelated to the same or the different Ln 3+ ions, respectively. In avoidance of the interference of the counteranion, a homoleptic dinuclear ([Ln 2 (Salen) 3 ] , ) or tetranuclear ([Ln 4 (Salen) 6 ] , ) framework is founded from the primitive structure unit of [Ln 2 (Salen) 3 ] n ( n = 1–2).…”

Structures and luminescent sensors of mixed‐counterions based salen‐type lanthanide coordination polymers

“…The Pr···Pr···Pr angles fall in the range of 87.0° to 129.5°, representing a significant distortion from the ideal tetrahedral angle of 109.5°. Such a topologic structure differ from that of {[Ce(H 2 L) 2 (NO 3 ) 2 ](PF 6 )·2CH 3 CN} n [H 2 L = N,N′ ‐bis (3‐methoxysalicylidene) cyclohexane‐1,2‐diamine] with the quartz Schläfli symbol {6 4 ·8 2 }, but similar to those for {[Ln(H 2 L SS )(NO 3 ) 2 Cl]·2CH 2 Cl 2 } n [Ln = La ( 1 ), Ce ( 2 ), and Nd ( 3 )] [H 2 L SS = trans ‐ N,N′ ‐bis‐(salicylidene)‐(1S,2S)‐cyclohexanediamine] …”

Crystal structure of (((1E,1′E)-(cyclohexane-1,2-diylbis(azanylylidene-κ2 N,N′))bis(methanylylidene))bis(2,1-phenylene))bis((2,6-diisopropylphenyl)amide-κ2 N′′,N′′′)manganese(II), C44H54N4Mn

“…The salen ligands and their derivatives, which feature of good chelating abilities, have been studied and reported by many researchers and are widely applied in chemical industry production [2][3][4][5][6][7]. Recently, we have developed the anilidoimine tetraazane ligands that possess bulky substitutes at the amine groups.…”