Structures for the 3d–5d–4f Heterotrimetallic Complexes: Synthesis, Structures, and Magnetic Properties

Abstract

Three new 3d–5d–4f heterotrimetallic complexes, [{Cu2(L)2Nd(H2O)}{W(CN)8}]n·2nH2O·nCH3CN (1), [{Cu2(L)2Sm(H2O)}{W(CN)8}]n·3nH2O (2), and [{Cu(L)Dy(H2O)5}{W(CN)8}]·2H2O (3) [L = N,N′‐ethylenebis(3‐methoxysalicylideneiminato) dianion] have been prepared and characterized both structurally and magnetically. The results indicate that complexes 1 and 2 show unique 1‐D chain structures while 3 displays a 0‐D trinuclear cluster structure. Interestingly, the structures of these 3d–5d–4f heterotrimetallic complexes are always changing and the coordination modes are mainly dependent on competitive relationships among various coordination bonds and/or hydrogen bonds. Magnetic measurements reveal the typical magnetic properties expected for the 3d–5d–4f spin systems in which complicated magnetic couplings and single ion magnetic anisotropy coexist.

The Influence of d‐f Coupling on Slow Magnetic Relaxation in NiIILnIIIMIII (Ln = Gd, Tb, Dy; M = Cr, Fe, Co) Clusters

“…The synthesis of these complexes is based on stepwise chemical self‐assembly. The first two steps are to synthesize corresponding precursors,[5e], Ni II (L) · H 2 O and [Ni(L)Ln](NO 3 ) 3 (Ln = Gd, Tb, Dy) according to general reaction conditions.…”

“…For [Cr(CN) 6 ], the structural parameters are overall comparable to that moiety presented in other relevant complexes. [5e], Due to the different atomic radius of M (M = Cr, Fe, Co), the C‐M bond lengths in complexes 1–3 show observable changing trend [C‐Cr (2.059(7)‐ 2.076(8) Å) > C‐Fe (1.933(5)‐ 1.946(5) Å) > C‐Co (1.877(8)‐1.906(9)) Å]) (Table S1). Besides, the different atomic radius is also reflected by the cell volumes of 1–5 (Table ), where the larger atomic radius corresponds to the larger cell volume r Cr > r Fe > r Co , V Complex1 > V Complex2 > V Complex3 ; r Gd > r Tb > r Dy , V Complex5 > V Complex4 > V Complex3 ).…”

“…However, this process is significantly affected by the symmetry of the local coordination sphere. [5a], Another important factor is the magnetic interactions between the central lanthanide metals and the surrounding paramagnetic centers. Some examples have proved that reasonable adjustment of these factors can achieve positive results.…”

“…In this field of research, some research groups including us has been working on the synthesis, structures and magnetic properties of the lanthanide based multi‐metal (The molecule contains more than three different metal elements) molecular systems and obtained many novel heterotrimetallic complexes with interesting magnetic properties . The reasons for the study of these systems are as follows: (1) the intrinsic nature of the lanthanide metal ions determines that they are very suitable for the design of a SMM.…”

“…In this work, we will discuss the Ni II (L)Ln III M III (H 2 L = N,N‐ethylenebis(3‐methoxysalicylaldiimine); Ln = lanthanide metal ions; M = Cr III , Fe III , Co III ) clusters, which are still relatively new as compared with the fully studied copper based compounds (Cu II (L)Ln III M III ). [5a], [5b], [5c] The low spin nickel ion just simplifies the three metal spin system into a two spin one. Our specific idea (Scheme ) is to switch metal ions of M from Cr III , Fe III to Co III .…”