C,N-chelated organotin(IV) trifluoroacetates. Instability of the mono- and diorganotin(IV) derivatives.

Synthesis, structural characterization and electrochemistry of C,N-chelated organotin(IV) dicarboxylates with ferrocenyl substituents

“…A possible bidentate coordination is prevented by the two bidentate C,N-chelating ligands at the tin atom (Sn1-N1 2.544 (4) Å, Sn1-N2 2.613(5) Å, Sn1-C1 2.123(4) Å a Sn1-C10 2.126(5)Å). The tin atom in 2 thus reveals a geometry similar to that found previously for [(L CN ) 2 Sn(OC(O)CF 3 ) 2 ] [11] and [(L CN ) 2 SnX 2 ] (X ¼ F, Cl, Br,I) [14b,20]. Ferrocene cyclopentadienyls in 2 assume intermediate conformations, departing by ca.…”

“…This observation is in contrast with the previously discussed 1 H NMR spectra of doubly C,N-chelated organotin(IV) halides and related compounds, where an AX pattern is typically seen for the CH 2 N protons and a broad signal found for the N(CH 3 ) 2 groups [14b]. On the other hand, we have found that [(L CN ) 2 Sn(OC (O)CF 3 ) 2 ] has a different 1 H NMR response since only one signal is detected for the CH 2 N fragment (d( 1 H) ¼ 3.73 ppm in THF-d8) and two broad resonances are observed for non-equivalent N(CH 3 ) 2 groups [11]. The expected doublet of H(6 0 ) (d( 1 H) ¼ 8.42 ppm) in the spectrum of 2 is somewhat broadened but still exhibits tin satellites with coupling constant 3 J( 119 Sn, 1 H) of ca.…”

“…The resonance at 4.19 ppm was assigned to protons of unsubstituted Cp' rings while the other two signals at 4.24 and 4.77 ppm were attributed to protons at the substituted ring. A relatively broad signal of the OC(O) fragment at 174.2 ppm in the 13 C{ 1 H} NMR spectrum suggests the presence of two equivalent monodentate carboxylates (bidentate carboxylic substituents exhibit this signal shifted to about 180 ppm) [8,9,11]. Neither the resonance of the C1 0 carbon [21] nor the signal attributable to C ipso (Cp) could be indentified owing to their low intensity or overlaps.…”

“…All these C,N-chelated organotin(IV) carboxylates featured monodentate carboxylate units in solution and in the solid state. In other contributions, we focused on the preparation, structural characterization and catalytic activity of tri-, di-and monoorganotin(IV) trifluoroacetates bearing C,N-chelating ligand (s) [11], and also on the preparation and structures of organotin(IV) acetates [12] and ferrocenecarboxylates [13] bearing additional phosphorus substituents in the carboxylate part. As an extension of our recent work, we report here on the reactivity of C,N-chelated tri-and diorganotin(IV) halides [14] towards potassium carboxylates in situ generated from simple and phosphine-substituted ferrocene carboxylic acids (Scheme 2).…”

S,N‐Chelated organotin(IV) compounds containing 6‐phenylpyridazine‐3‐thiolate ligand—structural, antibacterial and antifungal study

“…Based on the latter results one paper concerning the synthesis, structural characterization and potential use of some C,N-chelated organotin(IV) trifluoroacetates followed. [15] In this paper we report on the preparation of some new organotin(IV) compounds bearing potentially chelating S,Nligand(s) (L SN = 6-phenylpyridazine-3-thiolate) with the different coordination modes by two possible tautomeric forms. Structural investigation of prepared compounds in solution as well as in the solid state, and the results of in vitro antimycotical and antibacterial screening, are also discussed in this paper (for general NMR numbering of compounds see Scheme 1).…”