Silver complexes with succinimide as models for the interaction of silver(I) with the uracil residue

Abstract

Succinimide (HSuc) forms silver complexes óf compositions AgSuc and M[Ag(Suc)2] (with M = Na and Li). The crystals of the 1:1 complex belong to the monoclinic space group P2l jc, with a = 8.031 (4) Á, b = 13.306 (7) Á, c = 10.345 (2) Á, ß = 97.16 (3)°, and Z = 4 Ag2(Suc)2-H20 units per cell. The structure was refined on 1671 non-zero reflections (I > 2.5 (/)) to R = 0.038. This compound is best formulated as the Ag+ salt of the [Suc-Ag-Suc]* ion, in which silver is approximately linearly coordinated to deprotonated nitrogen atoms of two succinimide anions. The other half of silver atoms form moderately strong bonds with two carbonyl groups of one anion, one carbonyl group of another anion, and one water molecule, in a roughly tetrahedral pattern. Li [ Ag(Suc)2] •4 is orthorhombic, space group Pnma, with a = 12.091 (2) Á, b = 8.934 (1) Á, c = 12.981 (2) Á, and Z = 4. The structure was refined on 1351 non-zero reflections (/ > 2.5 ( )) to R = 0.026. The unit cell contains the linear [Suc-Ag-Suc]" ion observed in the previous compound. The Li+ ion is surrounded by four water molecules in a roughly tetrahedral arrangement. These water molecules form H bonds with the carbonyl groups of the anions. The and 13C NMR spectra of the succinimide complexes are consistent with the presence of two-coordinate [Suc-Ag-Suc]" anions in solution, and the close similarity in the spectra of the M[Ag(Suc)2] complexes for M = Li+, Na+, and Ag+ suggests that, in the last case, the Ag-0 interactions found in the crystal are not maintained in solution. Various regions of the IR spectra can be used to detect metal complexation to the deprotonated nitrogen site of succinimide, but direct binding of silver to the carbonyl groups in Ag[Ag(Suc)2] produces no obvious diagnostic signals in the spectra.Li [ Ag(Suc)2] •4 20 structure including refined temperature factors (Table XI), weighted least-squares planes (Table XII), distances involving the hydrogen atoms (Table XIII), and observed and calculated Structure factor amplitudes (Table XIV), and infrared spectra of succinimide and its silver complexes (Figure 6) (36 pages). Ordering information is given on any current masthead page.

Organophosphine/phosphite‐stabilized silver(I) complexes bearing N‐hydroxysuccinimide ligand: synthesis, solid state structure and their potential use as MOCVD precursors

“…In the complexes, the C = O stretching vibration are shifted to lower frequency (about 33–77 cm −1 ) compared to the free N ‐hydroxysuccinimide ligand (1706 cm −1 ). These changes, which are correlated with those found for the uracil moiety, could be ascribed to the delocalization of the anionic charge into the ring and carbonyl groups, thus decreasing the C = O bond order (Scheme ).…”

“…These changes, which are correlated with those found for the uracil moiety, [29] could be ascribed to the delocalization of the anionic charge into the ring and carbonyl groups, thus decreasing the C = O bond order (Scheme 2).…”

Interactions de l'ion Ag+ avec la glutarimide

“…Toutefois, la structure de ces espkces n'a pu &tre dtterminte sur des tchantillons solides a cause de leur grande solubilitt et de l'instabilitt de leurs solutions saturtes. Avec la mCthyl-1 thymine (HMT, 2), un compost de formule (4,5) comme pour les dtrivts de l'uracile. Le prtsent article dtcrit les rtsultats obtenus avec la glutarimide (HGlu, 4), qui posskde un cycle a six atomes la rapprochant de I'uracile et la thymine.…”

The Reactivity of Ambident Nucleophiles: Marcus Theory or Hard and Soft Acids and Bases Principle?

“…The gas phase experiments have been carried out to avoid the common solvent effects, and tetrabutylammonium ions have been used to replace metal ions in order to remove the complication of counter metal ions . We will exclude solvents, but will explicitly include counter ions in our calculations for three considerations: (1) the alkali and transition metal ions generally show opposite regioselectivity for the ambident nucleophilic reactions; (2) Perron et al and Tao et al obtained crystal structures of the silver salt of succinimide in order to model the interaction between silver (I) and the uracil residue; (3) the lithium enolates could further aggregate into larger dimmers/tetramers and solvated dimmers/tetramers …”