Intermetallic Interactions Within Solvated Polynuclear Complexes: A Misunderstood Concept

Abstract

For polynuclear gas-phase [M m L n ] z+ complexes comprising cationic metals and neutral ligands, the simple use of the Coulomb equation [Eq.(1)] usually gives a preliminary but

Thermodynamics, Structure and Properties of Polynuclear Lanthanide Complexes with a Tripodal Ligand: Insight into their Self‐Assembly

“…The significance and origin of the microscopic descriptors in Equation (11) have been discussed in details by Piguet41 and this thermodynamic model has already found several applications 32. 42 Herein, we will apply the modelling to the self‐assembly processes occurring between Ln III and L10 [Equilibria (7)–(10)]. However, a sufficient knowledge of the structural organisation of complex species is required for evaluating the number of homo‐ and hetero‐component interactions and the symmetry‐related statistical factors.…”

“…The effective molarity has been also estimated for tripodal complexes with L1 a , which possesses a spacer between the NO 2 binding sites and the anchor that is longer than that of L10 by only one CH 2 . The value of ${c{{{\rm eff}\hfill \atop {\rm tripod}\hfill}}}$ ≈10 −4 M 42 still allows the formation of tripodal complexes despite the appearance of the complexes [Ln L1 a 2 ] 3+ in the presence of excess ligand. In the case of mononuclear complexes [Ln L10 ] 3+ , the effective concentration should be reduced even more (${c{{{\rm eff}\hfill \atop {\rm tripod}\hfill}}}$ ≪10 −4.0 M ) due to significant structural strains hindering the formation of intramolecular connections.…”

Innovative Multipodal Ligands Derived from Tröger's Bases for the Sensitization of Lanthanide(III) Luminescence

“…A 2:4 system could thus be constructed from the octahedron generated by two rhombs intertwined around the axis that includes the Tb III ions, with each rhomb formed of two ligand molecules and two Ln III (Figure 5). These rhomboidal structures, in which two vertices are formed by TB bridges and the other two by lanthanide(III) ions, have the same structures as the self‐assembly compounds formed between TBs and other transition‐metal ions [34, 49–57] . Even though the general stoichiometry of these coordination compounds is 2:2, Lützen and co‐workers proposed structures with two transition‐metal ions and three TB ligands, showing that a 2:4 structure could also be obtained from a steric point of view [49, 50] .…”

“…By analogy, we suggest that the actual coordination compounds obtained with 1:1 Tb III /ligand ratios ( 3 b , c and 4 a – c ) are in fact 2:2 systems formed by rhomboidal structures with two terbium(III) ions located in two vertices and the diazocinic cores of the two TB ligands in the remaining ones (Figure 6). It should be noted, however, that the structures proposed for the Tb III coordination compounds for which the number of coordinated solvent molecules ( q ) values could not be determined experimentally are hypothetical and are only suggested upon considering similar complexes [34, 49–57] …”

Prevention of postoperative adhesion formation by individual and combined administration of 4 per cent icodextrin and dimetindene maleate (Br J Surg 2009; 96: 1476–1483)

“…Lützen's second observation, this time together with Piguet, was in an experimental and theoretical analysis of metal–metal interactions in solution. They point to two effects that oppose each other: Coulombic interactions produce large intermetallic repulsion at short distances, and solvation effects result in large intermetallic attractions for small pseudo‐spherical ions with short intermetallic separations 120…”