title: Molecular Assemblies of Metal Complexes via Base-Pairing of Nucleic Acids in the Crystalline State.
abstract: The nature of the molecular assemblies formed in the crystalline state by cobalt(II) terpyridine (terpy) complexes incorporating appended adenine (A) or thymine (T) bases was found to be controlled by which bases are present. Single-crystals of the cobalt(II) complexes [Co(A-C6-terpy)2](BF4)2(1) and [Co(T-C6-terpy)2](BF4)2(2) have needle and block habits, respectively. Subsequent mixing of 1 and 2 in MeOH resulted in isolation of [Co(A-C6-terpy)1.5(T-C6-terpy)0.5](BF4)2(3) as plate-like crystals. A 3D network structure is present in 1 that incorporates 1D chains, whereas 2 adopts a 2D stacked structure constructed from ladder-type assemblies. For 3, "dimer-rings" consisting of [Co(A-C6-terpy)2]2+and [Co(A-C6-terpy)(T-C6-terpy)]2+units are generated by means of base-pairing between A and T. Notably, 3 displays the first crystal structure of a heteroleptic cobalt(II) complex of [Co(A-C6-terpy)(T-C6-terpy)](BF4)2. These assembly differences involving the terpyridine cobalt(II) complex units in 1-3 affect the cooperativities influencing their spin crossover (SCO) behavior. The influence of the terminal nucleobases on the resulting assembly has been probed by investigating the co-crystallization of [Co(terpy)2](BF4)2(4) with [Co(C6-terpy)2](BF4)2(5) and 1 with 5.
authors.affiliation: Department of Chemistry, Graduate School of Science and Technology, Kumamoto University, 2-39-1, Kurokami, Chuo-ku, Kumamoto, 860-8555, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Nakaya
authors.affiliation: Department of Chemistry, Graduate School of Science and Technology, Kumamoto University, 2-39-1, Kurokami, Chuo-ku, Kumamoto, 860-8555, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Ohtani
authors.affiliation: Research & Utilization Division, Japan Synchrotron Radiation Research Institute, 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5198, Japan.
authors.forename: Kunihisa
authors.initials: K
authors.lastname: Sugimoto
authors.affiliation: Department of Chemistry, Graduate School of Science and Technology, Kumamoto University, 2-39-1, Kurokami, Chuo-ku, Kumamoto, 860-8555, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Nakamura
authors.affiliation: School of Chemistry, The University of Sydney, NSW, 2006, Australia.
authors.forename: Leonard F
authors.initials: LF
authors.lastname: Lindoy
authors.affiliation: Department of Chemistry, Graduate School of Science and Technology, Kumamoto University, 2-39-1, Kurokami, Chuo-ku, Kumamoto, 860-8555, Japan.|Institute of Pulsed Power Science (IPPS), Kumamoto University, 2-39-1, Kurokami, Chuo-ku, Kumamoto, 860-8555, Japan.
authors.forename: Shinya
authors.identifier: http://orcid.org/0000-0001-8392-2382
authors.initials: S
authors.lastname: Hayami
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives; D020029:Base Pairing; D003035:Cobalt / Q000737:chemistry*; D056831:Coordination Complexes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D009696:Nucleic Acids / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry; D013941:Thymine / Q000031:analogs & derivatives
chemical_list: D056831:Coordination Complexes; D009696:Nucleic Acids; D011725:Pyridines; D003035:Cobalt; D000225:Adenine; D013941:Thymine
keywords: cobalt complex; nucleobase; self-assembly; spin crossover; supramolecular chemistry