| Abstract |
Aliphatic and aromatic amidoximes RC(NH2)=QNOH (R = Et, tBu, Ph, o-ClC6H4) react with Zn(OAc)(2)center dot 2H(2)O in Me2CO giving [Zn(OAc)(2)\RC(NH2)=QNOH\(2)] complexes bearing N-bound amidoximes, which are involved in a moderate strength (7.3-11.9 kcal mol(-1) by the DFT calculations) intramolecular resonance-assisted hydrogen bonding between the oxime HO group and the oxo group of the acetate ligand. The complexes [Zn(OAc)(2)\RC(NH2)=QNOH\(2)] react with excess Zn(OTf)(2) in acetone accomplishing trinuclear species [Zn-3(mu(2)-OAc)(2)\mu(2)-RC(NH2)=QN(H)O\(4)(H2O)(6)](OTf)(4) featuring both O-ligated amidoximes-stabilized in the aminonitrone tautomeric form-and bridging acetate ligands. The aminonitrone trinuclear species were also prepared directly via the reaction of the amidoximes with Zn(OTf)(2) in EtOAc; ethyl acetate in this reaction plays the role of the acetate donor and OAc- is generated in situ via Zn-II-mediated hydrolysis of EtOAc. Although [Zn(OAc)(2)\RC(NH2)=QNOH\(2)] are inactive toward dimethylcyanamide, the [Zn-3(mu(2)-OAc)(2)\mu(2)-RC(NH2)=QN(H)O\(4)(H2O)(6)](OTf)(4) complexes readily react with Me2NCN giving, as a result of ZnII-mediated amidoxime-cyanamide coupling, the O-carbamidine amidoxime complexes [Zn(OTf)(2)\RC(NH2)=QNOC(NMe2)=QNH\(2)]. All synthesized compounds were characterized by HRESI-MS, FTIR, H-1-, CP-MAS TOSS C-13\H-1\-, and C-13\H-1\ NMR, and additionally by single-crystal X-ray diffraction for eight species. Different types of non-covalent interactions in the obtained solid-state structures were studied by DFT calculations (M06-2X/6-311+G(d,p) level of theory) and topological analysis of the electron density distribution within the formalism of Bader s theory (QTAIM method). |
