Control over the Self-Assembly Modes of Pt(II) Complexes by Alkyl Chain Variation: From Slipped to Parallel π-Stacks.
We report the self-assembly of a new family of hydrophobic, bis(pyridyl) Pt(II) complexes featuring an extended oligophenyleneethynylene-derived π-surface appended with six long (dodecyloxy (2)) or short (methoxy (3)) side groups. Complex 2, containing dodecyloxy chains, forms fibrous assemblies with a slipped arrangement of the monomer units (dPt⋅⋅⋅Pt ≈14 Å) in both nonpolar solvents and the solid state. Dispersion-corrected PM6 calculations suggest that this organization is driven by cooperative π-π, C-H⋅⋅⋅Cl and π-Pt interactions, which is supported by EXAFS and 2D NMR spectroscopic analysis. In contrast, nearly parallel π-stacks (dPt⋅⋅⋅Pt ≈4.4 Å) stabilized by multiple π-π and C-H⋅⋅⋅Cl contacts are obtained in the crystalline state for 3 lacking long side chains, as shown by X-ray analysis and PM6 calculations. Our results reveal not only the key role of alkyl chain length in controlling self-assembly modes but also show the relevance of Pt-bound chlorine ligands as new supramolecular synthons.
Institut für Organische Chemie and Center for Nanosystems Chemistry, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
Naveen Kumar
NK
Allampally
Institut für Organische Chemie and Center for Nanosystems Chemistry, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.|Departamento de Química Orgánica, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
María José
MJ
Mayoral
School of Chemistry and Chemical Engineering, Queen's Universtity Belfast, Stranmillis Road, Belfast, BT9 5AG, United Kingdom.
Sarayute
S
Chansai
School of Chemistry and Chemical Engineering, Queen's Universtity Belfast, Stranmillis Road, Belfast, BT9 5AG, United Kingdom.
María Cristina
MC
Lagunas
School of Chemistry and Chemical Engineering, Queen's Universtity Belfast, Stranmillis Road, Belfast, BT9 5AG, United Kingdom.
Christopher
C
Hardacre
Institut für Organische Chemie and Center for Nanosystems Chemistry, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
Vladimir
V
Stepanenko
São Carlos Institute of Chemistry, University of São Paulo, A, v. Trab. São-Carlense, 400, 13560-970, São Carlos-SP, Brazil.
Rodrigo Q
RQ
Albuquerque
Institut für Organische Chemie and Center for Nanosystems Chemistry, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany. fernandg@uni-muenster.de.|Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149, Münster, Germany. fernandg@uni-muenster.de.
Gustavo
G
Fernández
D000478:Alkylation; D018360:Crystallography, X-Ray; D057927:Hydrophobic and Hydrophilic Interactions; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009944:Organoplatinum Compounds / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*; D013816:Thermodynamics
D008024:Ligands; D009944:Organoplatinum Compounds; D011725:Pyridines
cooperative effects; noncovalent interactions; pi-interactions; self-assembly; solid-state structures