Solution and Solid State Structure of a Canted, Side-to-Face, Bis(porphyrin) Adduct

Area of Science:

• Coordination Chemistry
• Supramolecular Chemistry
• Materials Science

Background:

• Meso-pyridyl/phenyl porphyrins (PyPs) are versatile building blocks for self-assembling ordered pigment arrays.
• Axially ligated porphyrins can form either perpendicular or canted arrays, with canted adducts being less explored.
• Understanding the structural and electronic differences between these array types is crucial for designing functional materials.

Purpose of the Study:

• To report the detailed X-ray crystal structure of a novel canted porphyrin adduct, [Ru(TPP)(CO)(3'MPyP)] (1).
• To provide thorough spectroscopic characterization of compound 1 in solution, including dynamic NMR studies.
• To enable comparative analysis with perpendicular porphyrin arrays to understand structure-property relationships.

Main Methods:

• X-ray crystallography for detailed structural determination.
• Solution-state spectroscopy (UV-Vis, NMR) for characterization.
• Dynamic (1)H NMR to investigate NH tautomeric exchange.

Main Results:

• The detailed X-ray structure of the canted porphyrin adduct [Ru(TPP)(CO)(3'MPyP)] (1) was determined.
• Spectroscopic data, including dynamic (1)H NMR, were obtained and analyzed.
• Compound 1 crystallizes in the monoclinic space group P2(1)/a.

Conclusions:

• The structural and spectroscopic data of the canted adduct 1 are strategically important for comparison with perpendicular analogues.
• Comparative studies of canted and perpendicular porphyrin arrays can elucidate how pigment orientation influences physicochemical properties.
• This research aids in understanding the impact of 3D architecture on processes like photoinduced electron or energy transfer.