Supramolecular Dye Inclusion Single Crystals Created from 2,3,6‐Trimethyl‐β‐cyclodextrin and Porphyrins

Abstract

In Nature, chromophoric groups play various roles, such as oxygen carriers, electron donors, light sensitizers, which are achieved in many cases by control of their aggregation modes in proteins. Host-guest chemistry between cyclodextrins and porphyrins has attracted great interest from supramolecular chemists because of their unique structures and functions that mimic those of proteins with chromophoric prosthetic groups. To mimic Nature's contrivances, the host-guest systems between cyclodextrins and porphyrins have frequently been studied. It is really surprising, however, that to date no detailed structural information of these complexes has been obtained from single-crystal analysis. In 2011, we reported the first successful isolation of a dye inclusion single crystal (DISC) between 2,3,6-trimethyl-β-cyclodextrin (TMβCD) and 5,10,15,20-tetrapyridylporphyrin (TPyP), and analyzed its X-ray crystal structure. The crystal structure revealed not only the real complex mode but also the attractive orientation of TPyP in the DISC. Herein, we present new strategies to prepare DISCs of TMβCD for several porphyrins and provide crystal structures, details of the complex modes, and optical properties. We believe that the present study has various important implications not only for the basic crystal analysis of inclusion complexes but also for potential applications that use these single crystals.

Porphyrin-uptake in liposomes and living cells using an exchange method with cyclodextrin

“…To use for the exchange method, the 1$TMe-b-CDx complex was prepared according to a previously described procedure (Scheme 1 and Fig. S1C †), 20 and the formation of this material was conrmed by the UV-vis absorption and 1 H NMR spectroscopy ( Fig. 1E and 4).…”

Controllable Direction of Porphyrin Derivatives in Two Cyclodextrin Cavities

“…Cyclodextrins, which comprise a chain of six to eight d ‐glucose monomers connected through the C‐1 and C‐4 positions, provide hydrophobic cavities for guest molecules as water‐soluble solubilizing agents. In particular, porphyrin–trimethyl‐β‐cyclodextrin (TMe‐β‐CDx, comprising seven d ‐glucose monomers, Figure ) complexes with pseudorotaxane structures in which two meso ‐phenyl moieties penetrate the upper rim of two TMe‐β‐CDx molecules have been formed by using porphyrin derivatives with four phenyl substituents in the meso positions , , . When porphyrin derivatives with four phenyl moieties are incorporated into two TMe‐β‐CDx molecules, two types of phenyl moiety are present, namely, two penetrating the upper rim of the two TMe‐β‐CDx molecules and two sandwiched between the two TMe‐β‐CDx molecules.…”

Adsorption of tetrakis(4-sulfophenyl)porphyrin onto liposomal surfaces composed of neutral diacylphosphatidylcholine and release by cyclodextrin

“…Porphyrin derivatives can form a 1 : 2 complex with TMe-b-CDx. [24][25][26] Furthermore, all of the tetraphenylporphyrin (5) were released from the TMe-b-CDx cavities and transferred to the lipid membrane aer mixing the 5$TMe-b-CDx complex with liposome-1 at 30 C for 1 h. 25 Therefore, we attempted the exchange reaction of 3 from TMe-b-CDx cavities to lipid membranes or the formation of direct interactions between liposome surfaces and the 3$TMe-b-CDx complex. Aer mixing the 3$TMe-b-CDx complex with liposome-1 under the same conditions reported previously, 25 all peaks assignable to TMe-b-CDx in the 3$TMe-b-CDx complex remained in the 1 H NMR spectrum (blue circles in Fig.…”