title: Chemical reaction-inspired crystal growth of a coordination polymer toward morphology design and control.
abstract: This paper reports a novel crystal growth system of a coordination framework {[Cu3(CN)3{hat-(CN)3(OEt)3}]}n (1) (hat-(CN)3(OEt)3 = 2,6,10-tricyano-3,7,11-triethoxy-1,4,5,8,9,12-hexaazatriphenylene). The coordination polymer is crystallized through the reaction of 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (hat-(CN)6), ethanol, and copper(I) complex, involving the breaking and forming of covalent bonds. The crystal morphologies obtained in the present system contain dumbbells, cogwheels, and superlattices. Moreover, in the growth perpendicular to the c-axis, periodic ramification at regular interval is observed, affording superlattice morphologies. Observation of the growth of dumbbell crystals shows that the growth rates parallel and perpendicular to the crystallographic c-axis are quite different: the former shows a drastic change with the reaction duration, while the latter is almost constant. These results are reproduced as a simple reaction-diffusion system, indicating that chemical reactions on crystal surfaces play an important role in determining the macroscopic crystal morphologies.
authors.affiliation: Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Masaoka
authors.forename: Daisuke
authors.initials: D
authors.lastname: Tanaka
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kitahata
authors.forename: Sumiko
authors.initials: S
authors.lastname: Araki
authors.forename: Ryotaro
authors.initials: R
authors.lastname: Matsuda
authors.forename: Kenichi
authors.initials: K
authors.lastname: Yoshikawa
authors.forename: Kenichi
authors.initials: K
authors.lastname: Kato
authors.forename: Masaki
authors.initials: M
authors.lastname: Takata
authors.forename: Susumu
authors.initials: S
authors.lastname: Kitagawa