Elucidation of the key role of Pt···Pt interactions in the directional self-assembly of platinum(II) complexes

Abstract

Significance Molecular self-assembly provides a bottom-up platform to design supramolecular functional materials, attracting numerous interests in material sciences. The utilization of platinum(II) complexes as building blocks of supramolecular assemblies opens up the unique noncovalent Pt···Pt interaction as one of the driving forces, imparting the supramolecular materials with rich spectroscopic features. However, the exact role of Pt···Pt interactions in molecular assembly remains elusive. The current study combines experimental and computational techniques to elucidate the role of Pt···Pt interactions in the self-assembly process of a representative amphiphilic platinum(II) complex. This work demonstrates the directional role of Pt···Pt interactions in assisting the molecular assembly in an anisotropic manner, achieving the formation of ordered self-assembled structures.

Non-covalent interactions (NCIs) in π-conjugated functional materials: advances and perspectives

“…). Recently, Yam and co-workers 71 showed that the self-assembly of Pt( ii ) complex is the result of metallophilic interaction between two Pt( ii ) centres. Such assemblies often exhibit red-shifted absorption (along with new metal–metal-to-ligand charge transfer MMLCT transition) and emission, as well as enhanced quantum yield and longer lifetime.…”

Toward the Design and Construction of Supramolecular Functional Molecular Materials Based on Metal–Metal Interactions

“…250−252 Furthermore, the directional role of the noncovalent Pt•••Pt interactions in the self-assembly process has been elucidated through a combination of experimental and computational efforts. 254 The directional Pt•••Pt interactions have been found to be arising from the interactions between the p z and d z 2 orbital pairs, playing an important role in governing the self-assembly processes and kinetics for achieving the formation of ordered self-assembled architectures in an anisotropic manner. 254 Exploitation on metal complexes of Ni(II), 255 Pd(II), 256,257 Rh(I), 185,187,258 Au(III), 259,260 Cu(I), 261,262 Ag(I), 263 and Au(I) 264−267 that are capable of exhibiting metal−metal interactions has opened up new avenues in controlling the strength of the metal−metal interactions and the geometry of the complexes, leading to the development of new classes of supramolecular functional materials.…”

“…254 The directional Pt•••Pt interactions have been found to be arising from the interactions between the p z and d z 2 orbital pairs, playing an important role in governing the self-assembly processes and kinetics for achieving the formation of ordered self-assembled architectures in an anisotropic manner. 254 Exploitation on metal complexes of Ni(II), 255 Pd(II), 256,257 Rh(I), 185,187,258 Au(III), 259,260 Cu(I), 261,262 Ag(I), 263 and Au(I) 264−267 that are capable of exhibiting metal−metal interactions has opened up new avenues in controlling the strength of the metal−metal interactions and the geometry of the complexes, leading to the development of new classes of supramolecular functional materials. We believe that the design of supramolecular functional materials via sophisticated hierarchical assembly is a fascinating field and requires the collective efforts of researchers to develop new classes of materials with desirable functions, achievable through a fundamental understanding of the strengths and dynamics of the noncovalent interactions.…”

“…Such an approach is still at its infancy and requires further exploration into the delicate control of the supramolecular assemblies in both the thermodynamics and kinetics aspects, so as to achieve interesting and unique morphologies via rational design strategies, ultimately leading to the systematic control and fine-tuning of distinctive nanoaggregates. Apart from building one-dimensional self-assembled and coassembled materials via the formation of directional Pt···Pt and π–π interactions, the utilization of Pt···Pt interactions in the formation of higher-dimensional supramolecular hierarchies would remain a major challenge for future advances. − Very recently, Yam and co-workers reported the design and construction of a two-dimensional (2D) multilayered supramolecular network with hexagonal packing through the use of a C 3 -symmetric alkynylplatinum­(II) complex, which led to the formation of a porous supramolecular polymer membrane with functionality. − Furthermore, the directional role of the noncovalent Pt···Pt interactions in the self-assembly process has been elucidated through a combination of experimental and computational efforts . The directional Pt···Pt interactions have been found to be arising from the interactions between the p z and d z 2 orbital pairs, playing an important role in governing the self-assembly processes and kinetics for achieving the formation of ordered self-assembled architectures in an anisotropic manner .…”

“…Apart from building one-dimensional self-assembled and coassembled materials via the formation of directional Pt···Pt and π–π interactions, the utilization of Pt···Pt interactions in the formation of higher-dimensional supramolecular hierarchies would remain a major challenge for future advances. − Very recently, Yam and co-workers reported the design and construction of a two-dimensional (2D) multilayered supramolecular network with hexagonal packing through the use of a C 3 -symmetric alkynylplatinum­(II) complex, which led to the formation of a porous supramolecular polymer membrane with functionality. − Furthermore, the directional role of the noncovalent Pt···Pt interactions in the self-assembly process has been elucidated through a combination of experimental and computational efforts . The directional Pt···Pt interactions have been found to be arising from the interactions between the p z and d z 2 orbital pairs, playing an important role in governing the self-assembly processes and kinetics for achieving the formation of ordered self-assembled architectures in an anisotropic manner . Exploitation on metal complexes of Ni­(II), Pd­(II), , Rh­(I), ,, Au­(III), , Cu­(I), , Ag­(I), and Au­(I) − that are capable of exhibiting metal–metal interactions has opened up new avenues in controlling the strength of the metal–metal interactions and the geometry of the complexes, leading to the development of new classes of supramolecular functional materials.…”