Foregoing Rigidity to Achieve Greater Intimacy

Abstract

Interactions between the surfaces of planar and nonplanar molecules have generated considerable interest in materials chemistry [1,2] as critical elements for understanding twodimensional supramolecular assembly, molecular and chiral recognition, and heterogeneous catalysis. Carbon-rich balland bowl-shaped polyaromatic molecules, such as fullerenes and fullerene fragments or buckybowls, figure prominently in these studies. Fullerenes have been found to form solid constructs with planar metalloporphyrins with remarkably close contacts but without the need for matching their convex and concave faces.[3] Molecular self-organization of nonplanar polyaromatic bowls on a planar metal surface introduces the interesting additional factor of symmetry mismatch.[4] Studies of ordered structures formed by weakly bound corannulene, C 20 H 10 , on the Cu(110) surface examined by scanning tunneling microscopy (STM) have revealed interesting insights into their molecular interactions. However, the overall effect of these interactions on the geometry of the corannulene bowl could not be evaluated by the STM method. [4] In this work, we selected a system that allowed us to investigate the mutual structural influences of bowl-shaped polyarenes and a planar polynuclear metal unit upon their attractive interaction (Figure 1). Curving of the planar trimetal unit to match the convex surface of a p bowl may be required to form a stable metal-organic complex. Flattening of the bowl-shaped polyarene may also be anticipated, with both effects changing the strain energy of interacting partners and leading to "mutual curvature adaptations" at the molecular level. By selecting the highly Lewis acidic perfluoro-ortho-phenylenemercury C 18 F 12 Hg 3 complex as a planar trimetal unit (Figure 2, [Hg 3 ]), we have significantly enhanced molecular interactions with p bowls. Although [Hg 3 ] is known to form stable complexes with a number of single-ring and planar polycyclic aromatic hydrocarbons, [5] its binding to curved polyarenes has never been examined. DFT calculations for [Hg 3 ] show a positively charged electrostatic potential surface in the center of the trimercury complex, [6] thus making it an excellent electrophilic probe for solid-state interactions with the negatively charged surfaces of bowlshaped polyarenes. As the latter, we chose corannulene, C 20 H 10 , and monoindenocorannulene, C 26 H 12 (Figure 2).The former polyarene is the smallest subunit of the C 60 fullerene with a C 5v symmetry, [7] whereas the latter has a larger surface area and deeper bowl depth than corannulene with a symmetry reduced to C s . Although the expected complex formation in the [Hg 3 ·C 20 H 10 ] and [Hg 3 ·C 26 H 12 ] systems should be favored by electrostatic interactions, the geometry and symmetry mismatch of building units ([Hg 3 ] is planar with a D 3h symmetry) makes both systems unique models to examine fine-structure deformation effects resulting from molecular interactions between planar and nonplanar molecules. Additionally, indenocorannulen...

Mixed-stack architecture and solvatomorphism of trimeric perfluoro-ortho-phenylene mercury complexes with dithieno[3,2-b:2′,3′-d]thiophene

“…Dithieno[3,2-b:2',3'-d]thiophene 1 [31] was provided by Solvay, Inc. Trimeric perfluoro-o-phenylene mercury (I) was prepared according to the procedure described earlier by Sartori and Golloch [32] and purified by recrystallization from DCM [33]. DTA coupled with TGA experiments were performed under nitrogen with a Hitachi STA7200 SII NanoTechnology instrument (an aluminum crucible (45 µL) was used; heating rate was 10 °C/min).…”

Coordination chemistry of mercury-containing anticrowns. Synthesis and structure of an unusual discrete, double-decker sandwich complex of cyclic trimeric perfluoro-o-phenylenemercury with an aromatic hydrocarbon

“…A characteristic structural feature of this adduct is an unprecedented m 6 -h 2 :h 2 :h 2 :h 2 :h 2 :h 2 coordination of each benzene moiety with the Hg atoms of the neighbouring anticrown units [17]. Other tested arenes such as toluene, xylenes, mesitylene, biphenyl, naphthalene, phenanthrene, fluorene, triphenylene and pyrene [5,6] as well as nonplanar, bowlshaped corannulene and indenocorannulene [18] react with macrocycle 1 in a similar manner giving rise to 1:1 complexes of the analogous, although less symmetrical structure. Organic non-…”

Vibrational and DFT analysis of perfluoro-o-phenylenemercury compounds

“…Compound 1 was prepared following literature procedure [1,4]. Careful attention has devoted to purification because the existence of polymorphs.…”

“…CSD database reports 77 molecular complexes of 1, and the most part possess face-to-face interactions with aromatic p-ring donor and CeF$$$HeC interactions. Usually infrared spectra of 1 [4] in his molecular complexes are reported, but a detailed vibrational analysis doesn't exist; for this reason no effect of coordinated guests onto vibrational spectra of 1 are reported, although vibrational spectroscopy is a very useful approach in evaluation of intermolecular interactions. A computational modeling of electronic spectra [5] report only a partial assignment of some modes.…”