The First One-Pot Synthesis of Multinuclear 3d-4f Metal–Organic Compounds Involving a Polytopic N,O-Donor Ligand Formed in Situ

Abstract

In this work we present 16 new 3d-4f metal-organic comounds, which are synthesized by a one-pot method with one uncommon polytopic N,Odonor ligand formed in situ. All these compounds are characterized by single crystal X-ray diffraction, which reveals isomorphism for them and a special heterometallic trinuclear structure in a perfect linear arrangement. Within this trinuclear unit, the metal(3d)-O-metal(4f) angle and metal(3d)-to-metal(4f) distance is exceptionally small, to our best knowledge, which should present the smallest one in the literature. Moreover, the magnetic properties of partial compounds are explored, revealing that at high temperature paramagnetic behavior is observed and the slow decrease is mainly due to a crystal field effect, at the low temperature antiferromagnetic interaction or magnetic anisotropy operates.

Trinuclear NiII-LnIII-NiII Complexes with Schiff Base Ligands: Synthesis, Structure, and Magnetic Properties

“…3 ) 2 Ln](NO 3 ) (HL 6 = (Z)-2-methoxy-6-((phenylimino)methyl)phenol, Ln III = La, Pr, Gd, Tb) [17,18], and [{Ni{L 7 ) 1.5 } 2 Ln(OH)] (H 2 L 7 = 7,7 -(ethane-1,1-diyl)bis(quinolin-8-ol), Ln III = Eu, Tb, Gd) [19] Each of the terminal Ni II ions in the above complexes [11][12][13][14][15][16][17][18][19][20][21][22][23][24] is coordinated to three phenolato oxygen atoms and three nitrogen atoms, consisting of in situ formed (NiL) − metalloligand. The coordination geometry around the Ni II ions is distorted octahedral except in the case of [{Ni{L 7 ) 1.5 } 2 Ln(OH)] [19] in which the N 3 O 3 atoms create a regular trigonal-antiprismatic geometry around the Ni II ions. The N 3 O 3 coordination around each Ni II ion in the above complexes [11][12][13][14][15][16][17][18][19][20][21][22][23][24] imposes chirality thus, each Ni II ion is chiral with either a ∆ or a Λ configuration due to the screw coordination arrangement of the achiral ligands around the metal ion.…”

“…The coordination geometry around the Ni II ions is distorted octahedral except in the case of [{Ni{L 7 ) 1.5 } 2 Ln(OH)] [19] in which the N 3 O 3 atoms create a regular trigonal-antiprismatic geometry around the Ni II ions. The N 3 O 3 coordination around each Ni II ion in the above complexes [11][12][13][14][15][16][17][18][19][20][21][22][23][24] imposes chirality thus, each Ni II ion is chiral with either a ∆ or a Λ configuration due to the screw coordination arrangement of the achiral ligands around the metal ion. When two chiral molecules associate, both homochiral (∆-∆ or Λ-Λ) and heterochiral (∆-Λ) pairs are possible.…”

“…When two chiral molecules associate, both homochiral (∆-∆ or Λ-Λ) and heterochiral (∆-Λ) pairs are possible. Since the above complexes [11][12][13][14][15][16][17][18][19][20][21][22][23][24] crystallize in centrosymmetric space groups, molecules with ∆-∆ and Λ-Λ pairs coexist in the crystals to form racemic crystals. The Ln III ions present coordination modes which vary from distorted octahedral and quasi trigonal prism for O 6 coordination [14][15][16]22,23], capped trigonal prism and capped octahedron for O 7 coordination [14,15,22], square antiprism and bicapped octahedron for O 8 and NO 7 coordination [20,21,23,24], tricapped trigonal prism for O 9 coordination [19], and distorted icosahedron for O 12 coordination [11,12,17,18].…”

“…The crystallographically established metal cores in Ni 2 Ln complexes found in refs. [11][12][13][14][15][16][17][18][19][20][21][22][23][24] (a), [25][26][27][28][29][30][31][32][33][34] (b), [35][36][37][38] (c), [39] (d), [40][41][42] (e), (f) [43], and (g) [44,45].…”

Crystal structure of 7,7′-[(pyridin-2-yl)methylene]bis(5-chloroquinolin-8-ol)

“…8-Quinolinol and its derivatives are well-known chelating agents in analytical chemistry and bidentate ligands to metal ions in structural chemistry. Recently, multinuclear metal complexes based on the dimeric 8-quinolinol ligand, 1,1-bis(8hydroxyquinolin-7-yl)ethane, have been investigated (Zhu et al, 2012;Zhang et al, 2014;Wu et al, 2017;Gao et al, 2018). On the other hand, Yamato et al (1986Yamato et al ( , 1987 reported the aromatic-group-substituted dimeric 8-quinolinol derivatives, 1,1-bis(8-hydroxyquinolin-7-yl)-1-(4-methoxyphenyl)methane, 1,1-bis(8-hydroxyquinolin-7-yl)-1-(furan-2-yl)methane and 1,1-bis(8-hydroxyquinolin-7-yl)-1-(thiophen-2-yl)methane, to be candidates for antitumor agents.…”