Supramolecular Frameworks Built up from Red‐Phosphor­escent trans‐Re₆ Cluster Building Blocks: One Pot Synthesis, Crystal Structures, and DFT Investigations

Supramolecular Frameworks Based on Rhenium Clusters Using the Synthons Approach

“…It is not possible to distinguish the rhenium atoms coordinated with OH − from those coordinated with water molecules, since the H atoms have not been localized. These distances agree well with those found, for instance, in neutral trans -[{Re 6 Q i 8 }(TBP) a 4 (OH) a 2 ] (TBP = p - tert -butylpyridine) [ 29 ] and [{Re 6 S i 8 }(OH) a 2 (bpy) a 4 ]·bpy·4H 2 O and [{Re 6 S i 8 }(OH) a 2 (apy) a 4 ]·2apy·2H 2 O [ 34 ].…”

“…Several examples of cluster-based materials are built from supramolecular interactions and involve strong extended hydrogen bonding like H 3 O 2 − bridges. One can cite octahedral rhenium cluster complexes, which are related to the present work, as [{Re 6 Q i 8 }(H 2 O) a n (OH) a 6−n ] n −4 (Q: S, Se) [ 43 ], trans -[{Re 6 S i 8 }(CN) a 4 (OH) a 2-n (H 2 O) a n ] n−4 [ 63 ], or [{Re 6 S i 8 }(OH) a 2 (bpy) a 4 ]·bpy·4H 2 O [ 34 ].…”

“…Most of these investigations have been carried out by using amines or amino groups as functional ligands, which leads to complexes or supramolecular networks. One can note, for instance, the functionalization by azides [ 21 , 22 ], azolates [ 23 , 24 , 25 , 26 , 27 ], pyridine, and its derivatives [ 28 , 29 , 30 , 31 , 32 , 33 , 34 ]. When an additional cation, transition metal, or lanthanide is employed, then some extended coordination networks can be reached [ 35 , 36 ], as in the cases of phenantroline and Gd yielding a 2D framework [ 36 ], amines and Cu yielding a 2D framework [ 37 ], ethylenediamine and 3D transition metals yielding a 2D framework with resulting porosity [ 38 , 39 ], or salen salts [ 40 ].…”

“…In the course of our research dealing with extended networks built on hexarhenium chalcogenide clusters, we have focused our efforts on the cluster unit [{Re 6 Q i 8 }(OH) a 6 ] n− functionalized by the pyrazine ligand. Several materials have already been reported, built from H bonding, π−π interactions, and/or van der Waals contacts [ 28 , 34 , 41 , 42 ], sometimes with potential porosity [ 41 ]. It is still a highly challenging task to design new materials whose structures can be predicted in advance.…”

In Situ Generation of Active Molybdenum Octahedral Clusters for Photocatalytic Hydrogen Production from Water

“…The crystal structure was determined by single-crystal X-ray diffraction techniques and revealed complete substitution of F À by OH À ligands.Combining the structural data with chemical analysis allowed us to conclude that the formula of the crystallized species is (H 3 O) 2 [32] The OÀO distance involvingt wo hydroxido groups from two adjacent clusters are very short (2.614(5)), which is shorter than the value of 2.79 (2) o bserved, for example, in neutral Re 6 S i 8 (OH) a 2 L a 4 (L a = 4,4'-bipyridine or 4-aminopyridine) clusterunit based compounds. [33] All the attempts at obtaining (A) 2 ChemSusChem 2016, 9,1963 -1971 www.chemsuschem.org (5 % v/v)s olution. Under standard catalytic reaction conditions, ap artial solubilization of the cluster compound was observed, probably owing to the breaking of the hydrogen bonds of the (H 3 O) 2 No additional HER was detected after 5hof reaction and hydrogen production reached ap lateau after 24 hofl ight irradiation ( Figure 2).…”