Synthesis and Structural Features of [4,4′-Diisopropoxyester-2,2′-bipyridine], [Dichloro(4,4′-diisopropoxyester-2,2′-bi-pyridine)-platinum(ii)] and Its Dichloromethane Solvated Pseudo-Polymorph: Versatile Supramolecular Interactions

Abstract

The organic ligand 4,4 0 -diisopropoxyester-2,2 0 -bipyridine, C 18 H 20 N 2 O 4 (1), crystallizes in the triclinic crystal system P-1 and the molecule occupies a special position in the unit cell. In the crystal, molecules form stacks with partial overlapping of the pyridine rings. The Pt(II) dichloro complex of 1 crystallizes from a mixture of ethanol/hexane and from dichloromethane to form orange and yellow crystals, respectively. The orange non-solvated crystals of the (bipyridine)(dichloro)platinum(II) complex C 18 H 20 N 2 O 4 PtCl 2 (2) crystallize in the triclinic crystal system P-1 as well with two independent molecules in the unit cell. In the crystal packing, molecules form two types of dimers with Pt1ÁÁÁPt1A and Pt2ÁÁÁPt2A distances of 3.478 and 5.186 Å , respectively. The yellow crystals, as a solvated pseudo-polymorph C 18 H 20 N 2 O 4 PtCl 2 Á1.5 CH 2 Cl 2 (3) also crystallize in the triclinic crystal system P-1 with two independent molecules in the unit cell. In the crystal packing, molecules form Pt2ÁÁÁPt1ÁÁÁPt1AÁÁÁPt2A intermolecular contacts with alternating distances 3.501 and 3.431 Å , respectively, forming infinite chains. Graphical Abstract The dichloro(bipyridine)platinum complex, dichloro(4,4 0 -diisopropoxyester-2,2 0 -bipyridine)-platinum(II), forms single crystals as a stable non-solvated form and a solvated polymorph with dramatically different supramolecular structure and short contacts.Keywords X-ray diffraction Á [4,4 0 -diisopropoxyester-2, 2 0 -bi-pyridine] Á [dichloro(4, 4 0 -diisopropoxyester-2, 2 0 -bipyridine)-platinum(II)] Á Supramolecular interactions Á Pseudo-polymorphism

Synthesis of a platinacycle: determination of the structure and examination of the photophysical properties based on DFT calculations

“…When Pt-bipyridine complexes exhibit UV–vis absorption bands caused by intermolecular charge transfer, the concentration dependence deviates from the Lambert–Beer law. 32–34 It seems there is no such intermolecular effect on the UV–vis absorption spectra of 1 in CH 2 Cl 2 . The absorption at 543 nm of 1 is assignable to intramolecular ligand-to-ligand charge transfer and/or ligand-to-metal charge transfer, which were examined by DFT calculations in the following section.…”

Stability Tuning of Vapor-Adsorbed State of Vapochromic Pt(II) Complex by Introduction of Chiral Moiety

“…This form crystallized in the monoclinic centrosymmetric space group P 2 1 / n . This crystal contained only one crystallographically independent Pt­(II) complex, that is, one Pt­(II) cation, two Cl ligands, and one bpybe ligand with almost the same bond lengths as the isopropyl ester analogue (in the range of 2.003(4)–2.015(4) Å for Pt–N and 2.289(1)–2.298(1) Å for Pt–Cl). , Consequently, the unit cell contained two molecules with different chirality, R-1 and S-1 (Figure a). Each ester chain was oriented upside-down with respect to its closest neighbors.…”

A concerted evolution of supramolecular interactions in a {cation; metal complex; π-acid; solvent} anion-π system

“…Some lability of the primary set aggregates could be due to the comparable sizes of the flat [Pt(CN)4] 2and TCP components (and consequently their higher relative mobility), the variety and complexity of interactions involving PPh4 + cations, the significant polarizability of the positive potential around TCP π-acid due to the proximity of anionic species, 33 and the meddling action of CH2Cl2 solvent molecules. 49 The significant influence of the CH2Cl2 solvent is supported by the time-dependent crystallization processes that occur in more concentrated solutions compared to those used in solution studies, and in a comparable time scale of hours. The signatures of an evolution of supramolecular assemblies are also apparent in the spectral changes from solution NMR studies, although the character of these changes does not allow for a detailed and straightforward description of the process.…”