title: Metal-Mediated Assembly of 1,N(6)-Ethenoadenine: From Surfaces to DNA Duplexes.
abstract: The design of multinuclear metal complexes requires a match of the ligand-to-metal vectors and the preferred coordination geometries of the metal ions. Only a few ligands are known with a parallel orientation of N→M vectors that brings the metal ions into close proximity. We establish here the adenine derivative 1,N(6)-ethenoadenine (εA) as an ideal bis(monodentate) ligand. Scanning tunneling microscope images of alkylated εA on graphite surface clearly indicate that these ligands bind to Ag(I) ions. The molecular structures of [Ag2(1)2](ClO4)2 and [Ag2(2)2](ClO4)2 (1, 9-ethyl-1,N(6)-ethenoadenine; 2, 9-propyl-1,N(6)-propylenoadenine) confirm that dinuclear complexes with short Ag···Ag distances are formed (3.0256(3) and 2.984(1) Å, respectively). The structural motif can be extended to divalent metal ions, as was shown by determining the molecular structure of [Cu2(1)2(CHO2)2(OH2)2](NO3)2·2H2O with a Cu···Cu distance of 3.162(2) Å. Moreover, when introducing the 1,N(6)-ethenoadenine deoxyribonucleoside into parallel-stranded DNA duplexes, even dinuclear Ag(I)-mediated base pairs are formed, featuring the same transoid orientation of the glycosidic bonds as the model complexes. Hence, 1,N(6)-ethenoadenine and its derivatives are ideally suited as bis(monodentate) ligands with a parallel alignment of the N→M vectors for the construction of supramolecular metal complexes that require two metal ions at close distance.
authors.forename: Soham
authors.initials: S
authors.lastname: Mandal
authors.affiliation: Physikalisches Institut, Westfälische Wilhelms-Universität Münster , Wilhelm-Klemm-Strasse 10, 48149 Münster, Germany.
authors.forename: Can
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Chemistry, DST Thematic Unit of Excellence on Soft Nanofabrication, Indian Institute of Technology-Kanpur , Kanpur, Uttar Pradesh 208016, India.
authors.forename: Rajneesh K
authors.initials: RK
authors.lastname: Prajapati
authors.forename: Jutta
authors.initials: J
authors.lastname: Kösters
authors.affiliation: Department of Chemistry, DST Thematic Unit of Excellence on Soft Nanofabrication, Indian Institute of Technology-Kanpur , Kanpur, Uttar Pradesh 208016, India.
authors.forename: Sandeep
authors.initials: S
authors.lastname: Verma
authors.affiliation: Physikalisches Institut, Westfälische Wilhelms-Universität Münster , Wilhelm-Klemm-Strasse 10, 48149 Münster, Germany.|Institute of Functional Nano and Soft Materials, Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University , 199 Ren'ai Road, Suzhou, 215123 Jiangsu, People's Republic of China.
authors.forename: Lifeng
authors.initials: L
authors.lastname: Chi
authors.forename: Jens
authors.initials: J
authors.lastname: Müller
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000737:chemistry; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D015394:Molecular Structure; D013499:Surface Properties
chemical_list: D008670:Metals; C004981:1,N(6)-ethenoadenine; D004247:DNA; D000225:Adenine