Flexibility of inorganic tennis ball structures inducing anion selectivity.
Inorganic tennis balls (ITBs), [[{Pt(betmp)(dach)}(2)Cu](2)(X)][X](3) (in which X=ClO(4) (-) (3), NO(3) (-) (4), Cl(-) (5) and Br(-) (6); dach=trans-1,2-diaminocyclohexane and betmp=bisethylthiomethylidenepropanedioate) and [[{Pt(dteym)(dach)}(2)Cu](2)(PF(6))][PF(6)](3) (7; dteym=1,3-dithiepane-2-ylidenemalonate), were prepared as crystals. Investigation of their X-ray crystal structures revealed that shapes of the cavities in ITBs show significant distortions that depend on the properties of the encapsulated anions. The CuCu* distance was observed to be longest in 7 and shortest in 5, the difference between them being 2.05 A. The flexibility of cavity structures of ITBs makes it possible to encapsulate various anions inside the cavity, while their distortions may be a reason for the difference in the encapsulating ability for anions, that is, anion selectivity. Especially, the distortions observed in 7 are so severe that the encapsulating ability of the cavity for PF(6) (-) is very low compared to other anions. The shapes of ITBs with ClO(4) (-) and BF(4) (-) ions inside their cavities are very similar; however, ClO(4) (-) is encapsulated by the cavity better than BF(4) (-), which is explicable by the difference of metal-anion interactions. This structural study on ITBs gives a clue to the origin of the anion selectivity of the cavity in ITBs previously investigated by (19)F NMR spectroscopy of the ITBs in methanol.
Kim
Ki-Hyun
KH
Department of Chemistry, Division of Nano Sciences and Center for Biomimetic Systems, Ewha Womans University, Seoul 120-750, Korea.
Park
Jung Su
JS
Kang
Tae Yi
TY
Oh
Kyungeun
K
Seo
Mi-Sook
MS
Sohn
Youn Soo
YS
Jun
Moo-Jin
MJ
Nam
Wonwoo
W
Kim
Kwan Mook
KM
D000838:Anions / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D003514:Cyclohexylamines / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry; D009944:Organoplatinum Compounds / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization
D000838:Anions; D003514:Cyclohexylamines; D009942:Organometallic Compounds; D009944:Organoplatinum Compounds; D003300:Copper; C030435:1,2-cyclohexanediamine