Ag^I Metallacoronates and Hg^II Metallacryptates Derived from a Catechol‐Based Aroylbis(N,N‐diethylthiourea)

Abstract

Reactions of mixtures between Ag(NO 3 ) and alkaline earth nitrates with the bifunctional ligand 2,2′-{1,2-phenylenebis[oxyacetyl(N,N-diethylthiourea)]}, H 2 L cat , give {2}-metallacoronates of the composition {M ⊂ [Ag 2 (L cat ) 2 ]} (M = Ca 2+ , Sr 2+ , or Ba 2+ ). The trinuclear assemblies show further aggregation in the solid state, where they establish dimeric or polymeric entities stabilized by weak Ag···N (amide) interactions. Discrete {2}-[a]

Gold-Based Coronands as Hosts for M3+ Metal Ions: Ring Size Matters

“…This non-equivalence is due to the rigidity of the formed assemblies and hindered rotation around the C-NEt 2 bonds. Similar effects were found for other complexes with {L1 ethyl } 2− ligands [ 39 , 40 , 41 , 42 , 43 ], but are also typical for chelate complexes with the parent benzoylthioureato ligands, where a rotational barrier of approximately 650 kJ/mol was found [ 54 ]. The 13 C NMR spectrum shows the signals in the expected regions.…”

“…This gives access to the syntheses of a large variety of multinuclear, bimetallic complexes (types II , II , IV , VI and VII in Figure 1 ). They are usually formed by simple one-pot reactions in solutions containing the ligands and mixtures of two metal ions with different Pearson’s acidity [ 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ]. Particularly interesting bonding features are established with ‘soft’ metal ions such as Ag + or Au + , where no chelate formation was found, but a monodentate coordination to the sulfur atoms of the ligands is observed.…”

“…Particularly interesting bonding features are established with ‘soft’ metal ions such as Ag + or Au + , where no chelate formation was found, but a monodentate coordination to the sulfur atoms of the ligands is observed. As a result, macrocyclic, coronand-type ligands were formed, which can accommodate one or two alkaline earth metal ions [ 30 , 41 ]. The ready formation of such assemblies raises questions concerning the mechanism of their formation, the role of the (central) metal ion(s) and if the resulting ring size is exclusively determined by the used precursors H 2 L1 R or H 2 L2 R .…”

Syntheses, Structures, and Magnetism of Trinuclear Zn2Ln Complexes with 2,6‐Dipicolinoylbis(N,N‐diethylthiourea)

“…[15] However, only a limited number of d transition metal complexes of H 2 L have been reported. [15][16][17][18] This is really surprising since iso-phthaloyl bis(N,N-dialkylthioureas), analogous thiourea ligands of H 2 L, could form symmetric dinuclear -bischelate complexes (I) ( Figure 1) with many 3d transition metal ions. [19][20][21] Very recently, we found that the reactions of H 2 L with common transition metal ions do not form dinuclear -bischelate complexes like I but the asymmetric dinuclear complex II (Figure 1).…”

“…The observed μ eff values at room temperature are all closed to the calculated values. Fitting χ M and M data of [Zn 2 Gd(L) 2 (OAc) 3 ] (1d) shows a g iso value of 1.94. in a wide range, such as alkali metal, [17] alkali earth metal [16,18] or lanthanide ions. [16] This finding and the increase of attention devoted to 3d-4f based magnetic materials motivates us to synthesize a series of 3d-4f mixed metals complexes with structural resemblance to III and to study their magnetic property.…”