Rhenium(i)-based bridgeless double metallocalix[4]arenes

Abstract

Bridgeless double metallocalix[4]arenes possessing two orthogonally arranged dinuclear cavitands were obtained from a Re2(CO)10, rigid bis-chelating OO donor (H2-L), and a flexible bis-ditopic NN donor (L') by a one-pot approach.

Rhenium‐Carbonyl‐Based Supramolecular Coordination Complexes: Synthesis, Structure and Properties

“…Utilizing similar design strategy by using a new tetratopic ligand (2,2',4,4',6,6'-hexamethylbiphenyl-3,3',5,5'-tetrakis(methylene))tetrakis(benzimidazole), the same group also presented a bicyclic metalla-calix [4]arene 32 where the two metalla-calix [4]arene units are connected together through a single bond without having any bridging units unlike the previous metallacycle 31 (Scheme 8). [110] Thus slight modifica-tion in the coordinating ligands completely altered the final shape of the metallacycle. Apart from traditional cavitands, these two examples described above provided the encouragement to assemble functional metallocavitand scaffolds possessing multiple guest-binding sites.…”

“…Scheme 8. Re(I)-based bridgeless bicalixarene 32 and its crystal structure (below) (in the crystal structure, carbonyl groups have been removed for clarity) [110] . 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 the one-step synthesis of alkoxy-bridged metallacycles (33a-33c) featuring the tertratopic ligand 1,2,4,5-tetraethynyl(4pyridyl)benzene.…”

Solvent-Directed Rhenium(I) Metallocyclic Tubes, Dimeric Capsule, and Intercalated Dimers

“…The dimensions, metal core, internal cavity, and functional units of metallocycles are the key factors for the further utilization of these supramolecular coordination complexes (SCCs) in the field of molecular recognition, catalysis, biomedicine, and chemical sensing . Among the many metal–organic macrocycles, bowl-shaped molecules, known as metallocavitands, synthesized from various naked/partially protected metal ions have attracted much research interest. − For instance, considerable attention has been devoted to the construction of fac -[Re­(CO) 3 ] core-based metallocycles. − Over the past few years, neutral flexible bidentate donors consisting of diphenylmethane (−Ph–CH 2 –Ph−) or dimesitylenemethane as the central spacer and two terminal heterocycles, (benzimidazolyl/naphthanoimidazolyl/2-alkyl- or 2-phenyl-substituted benzimidazolyl), have been used in the self-assembly of dinuclear heteroleptic or mononuclear homoleptic metallocavitands. This assembly is achieved using a rigid bis-chelating donor, flexible bidentate ligands, and rhenium sources in the presence of high-boiling aromatic solvents via a one-pot solvothermal approach .…”

Self-assembly of thiolato-bridged ester-functionalized Re(i)-based tetranuclear spiro-metallacyclophanes

“…Nevertheless, the flexibility of ligands is crucial to manifest diverse kinds of structural motifs. 79,80 This inspired us to proceed with flexible and functionality-containing tetradentate ligands to arrive at the geometrical features of thiolatobridged Re(I)-based metallacyclophanes.…”