title: From ring-in-ring to sphere-in-sphere: self-assembly of discrete 2D and 3D architectures with increasing stability.
abstract: Directed by increasing the density of coordination sites (DOCS) to increase the stability of assemblies, discrete 2D ring-in-rings and 3D sphere-in-sphere were designed and self-assembled by one tetratopic pyridyl-based ligand with 180° diplatinum(II) acceptors and naked Pd(II), respectively. The high DOCS resulted by multitopic ligand provided more geometric constraints to form discrete structures with high stability. Compared to reported supramolecular hexagons and polyhedra by ditotpic ligands, the self-assembly of such giant architectures using multitopic ligands with all rigid backbone emphasized the structural integrity with precise preorganization of entire architecture, and required elaborate synthetic operations for ligand preparation. In-depth structural characterization was conducted to support desired structures, including multinuclear NMR ((1)H, (31)P, and (13)C) analysis, 2D NMR spectroscopy (COSY and NOESY), diffusion-ordered NMR spectroscopy (DOSY), multidimensional mass spectrometry, TEM and AFM. Furthermore, a quantitative definition of DOCS was proposed to compare 2D and 3D structures and correlate the DOCS and stability of assemblies in a quantitative manner. Finally, ring-in-rings in DMSO or DMF could undergo hierarchical self-assembly into the ordered nanostructures and generated translucent supramolecular metallogels.
authors.affiliation: Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University , Shanghai 200062, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Sun
authors.forename: Ming
authors.initials: M
authors.lastname: Wang
authors.forename: Zhichao
authors.initials: Z
authors.lastname: Lou
authors.forename: Mingjun
authors.initials: M
authors.lastname: Huang
authors.forename: Chenglong
authors.initials: C
authors.lastname: Xu
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Li
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Chen
authors.forename: Yihua
authors.initials: Y
authors.lastname: Yu
authors.forename: Grant L
authors.initials: GL
authors.lastname: Davis
authors.forename: Bingqian
authors.initials: B
authors.lastname: Xu
authors.forename: Hai-Bo
authors.initials: HB
authors.lastname: Yang
authors.forename: Xiaopeng
authors.initials: X
authors.lastname: Li
mesh_terms: D018360:Crystallography, X-Ray; D005782:Gels / Q000737:chemistry; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*
chemical_list: D005782:Gels; D008024:Ligands; D009942:Organometallic Compounds; D011725:Pyridines; D010984:Platinum; D010165:Palladium