title: The role of 2,6-diaminopyridine ligands in the isolation of an unprecedented, low-valent tin complex.
abstract: Stabilization of the central atom in an oxidation state of zero through coordination of neutral ligands is a common bonding motif in transition-metal chemistry. However, the stabilization of main-group elements in an oxidation state of zero by neutral ligands is rare. Herein, we report that the transamination reaction of the DAMPY ligand system (DAMPY=2,6-[ArNH-CH2 ]2 (NC5 H3 ) (Ar=C6 H3 -2,6-iPr2 )) with Sn[N(SiMe3 )2 ]2 produces the DIMPYSn complex (DIMPY=(2,6-[ArNCH]2 (NC5 H3 )) with the Sn atom in a formal oxidation state of zero. This is the first example of a tin compound stabilized in a formal oxidation state of zero by only one donor molecule. Furthermore, three related low-valent Sn(II) complexes, including a [DIMPYSn(II) Cl](+) [SnCl3 ](-) ion pair, a bisstannylene DAMPY{Sn(II) [N(SiMe3 )2 ]2 }2 , and the enamine complex MeDIMPYSn(II) , were isolated. Experimental results and the conclusions drawn are also supported by theoretical studies at the density functional level of theory and (119) Sn Mössbauer spectroscopy.
authors.affiliation: Institute of Inorganic Chemistry, Graz University of Technology, 8010 Graz (Austria), Fax: (+43) 316-873-32102.
authors.forename: Johanna
authors.initials: J
authors.lastname: Flock
authors.forename: Amra
authors.initials: A
authors.lastname: Suljanovic
authors.forename: Ana
authors.initials: A
authors.lastname: Torvisco
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schoefberger
authors.forename: Birgit
authors.initials: B
authors.lastname: Gerke
authors.forename: Rainer
authors.initials: R
authors.lastname: Pöttgen
authors.forename: Roland C
authors.initials: RC
authors.lastname: Fischer
authors.forename: Michaela
authors.initials: M
authors.lastname: Flock
keywords: Mössbauer spectroscopy; density functional calculations; diaminopyridine ligands; diiminopyridine ligands; donor-acceptor systems; tin