Topological insights in polynuclear Ni/Na coordination clusters derived from a schiff base ligand

Abstract

where H 2 L1 is the semi-rigid Schiff base ligand (E)-2-(2-hydroxy-3-methoxybenzylideneamino)-phenol). Compound 1 possesses a rare Ni 3 II Na I cubane (3M4-1) topology, and compound 2 is the first example in polynuclear Ni/Na chemistry that exhibits a 2,3,4M7-1 topology.

Butterfly-like Heteronuclear 3d–4f Metal Clusters: Synthesis, Structures, Magnetic Properties, and Magnetocaloric Effect

“…After this, a graph representation of a butterfly-like Fe 3 LnFe 3 skeleton was obtained (Figure b) by simplifying all the bridging oxygen centers into metal–metal edges. A topological analysis of the resulting skeleton graph revealed a trinodal 2,3,4-linked Fe 6 Ln cluster with a rare type of 2,3,4M7-1 topology . It is defined by a (3 2 .4) 4 (3 2 )­(3) 2 point symbol with the (3 2 .4), (3 2 ), and (3) notations corresponding to the 3-linked central Fe atoms, the 4-linked Ln atom, and the 2-linked lateral Fe atoms, respectively.…”

“…Figure presents the temperature dependence of −Δ S m calculated for 2 . −Δ S m attains the highest value of 10.6 J kg –1 K –1 (16.3 J mol –1 K –1 ) at 7.0 T and 2.0 K. This value lies within the range reported for other gadolinium–iron clusters, ,− thus confirming a possible use of this type of compound for magnetic refrigeration. Although the −Δ S m parameter of 2 is inferior in comparison to some other compounds containing several lanthanide centers (Table S2 in the Supporting Information), it is superior or comparable to the values reported for Gd–Fe metallocrowns and clusters containing one lanthanide center .…”

“…A topological analysis of the resulting skeleton graph revealed a trinodal 2,3,4-linked Fe 6 Ln cluster with a rare type of 2,3,4M7-1 topology. 47 It is defined by a (3 2 .4) 4 (3 2 )(3) 2 point symbol with the (3 2 .4), (3 2 ), and (3) notations corresponding to the 3linked central Fe atoms, the 4-linked Ln atom, and the 2-linked lateral Fe atoms, respectively. Notably, the present type of topology has not been documented for heterometallic Fe/Ln clusters.…”

Salicylaldimines: Formation via Ring Contraction and Synthesis of Mono- and Heterobimetallic Alkali Metal Heterocubanes

“…Heterobimetallic SAI complexes are rare and comprise transition metal complexes linked to alkali metals by additional donor substituents in the ligand periphery (e.g., Scheme b). ,, In olefin polymerization, the heterobimetallic species show enhanced catalytic activities or improved molecular weight control compared to their monometallic counterparts. , Heterobimetallic complexes with both metals being main group metals have so far only been realized in a series of alkali metal aluminate complexes (Scheme c) . The intriguing cubic and double cubic structural motifs found in alkali metal SAI complexes (Scheme a) have so far not been authenticated for heterobimetallic SAI species.…”