Organische Metallkomplexe, XX. Strukturen der Quecksilber (II)‐Verbindungen von Stickstoff‐ und Schwefel‐Analoga des 2,2,6,6‐Tetramethyl‐3,5‐heptandions

Abstract

Dipivaloylmethan (2,2,6,6‐Tetramethyl‐3,5‐heptandion, 4) bindet Hg(II) am mittleren Kohlenstoff zu 2. Ersetzt man einen Sauerstoff durch Stickstoff, so läßt sich ein cyclisches Trimeres 16 isolieren, in dem die Röntgenstrukturanalyse gleichfeste Bindungen von Hg(II) an C‐5 (2.10 Å) und N‐1 (2.08 Å) anzeigt; die Sauerstoffatome sind weiter entfernt (HgO 2.53 Å). Im Monothio‐Derivat 14 sind zwei Liganden über die Schwefelatome angenähert linear (174°) an Hg(II) gebunden (HgS 2.35 Å). Die Sauerstoffatome der Acylreste sind in beiden Fällen weiter entfernt (HgO in 16 2.53 Å, in 14 2.65 Å). Für den Hg‐Komplex des Liganden 9 mit Stickstoff und Schwefel wird die unsymmetrische Struktur 15 vorgeschlagen.

Mercury(II) Complexes Containing the [Hg(L)2]2–, [Hg(L)(HL)]−, and [Hg(HL)2] Units [H2L = 3-(2-Chlorophenyl)-2-sulfanylpropenoic Acid]. Structural and Spectroscopic Effects of the Different Degrees of Ligand Protonation

“…Recent surveys of Hg(II) thiolate structures show values for these Hg–S distances in the range 2.32–2.36 Å for linear [Hg(SR) 2 ] complexes, 2.42–2.45 Å for trigonal [Hg(SR) 3 ] − species and 2.52–2.58 Å for tetrahedral [Hg(SR) 4 ] 2– ones. The data for 1 and 2 , as well as for other equivalent sulfanylcarboxylates (or in other complexes with S,O-donor ligands ,,− ), show that the increase in the Hg–S bond length is not significant when the coordination number increases on the basis of the O-donor atom but that the S–Hg–S angle is quasi-linear. A similar situation also occurs when the Hg atom of an [Hg(SR) 2 ] thiolate bonds pyridine to give a tricoordinated T-shaped complex, a carboxylate group to give a seesaw-shaped geometry, or when, as in 3· 4H 2 O, a secondary intermolecular interaction increases the Hg coordination number.…”

“…The two chelate HgSCCO rings (rms 0.137) are coplanar and make angles of 49.8(1)° with the Cl–C 6 H 4 plane. The data were compared with those for the equivalent neutral examples containing S,O-bidentate ligands available in the literature, including complexes of thiosalicylic acid, , monothioderivatives of 2,2,6,6-tetramethyl-3,5-heptanedione, , 2-dimethylamino-3,4-dioxo-cyclobut-1-en thiolate, and N -(piperidyl-thiocarbonyl)benzamide . The closest situation for the Hg kernel is that of the thiosalicylic acid complex described in ref , which was isolated as a dioxane solvate.…”

Intramolecular Coordination in Organometallic Compounds of Groups 2, 12, and 13

“…The reaction of mercury(II) perchlorate trihydrate with 5-amino-2,2,6,6-tetramethyl-4-hepten-3-one in a 1:1 ratio in methanol yielded a colorless crystalline complex (mp = 225 °C under decomposition). 136 The cationic and anionic FAB mass spectra indicated the complex to be a trimer. An X-ray analysis revealed that the structure of 189 was that of a cyclic trimer (Scheme 96).…”

“…To investigate the occurrence of IC in organomercury compounds, 2-Me2NCH2C6H4HgX [ArHgX; X = Cl (136), OAc (137)], (2-Me2NCH2C6H4)2Hg (Ar2Hg; 138), and (S)-2-Me2NCH(Me)C6H4HgX [(S)-ArHgX; X = Cl (139), OAc (140)] were synthesized (Scheme 76).102 Scheme 76 Ar2Hg, ArHgCl, and (S)-ArHgCl were obtained from the corresponding ArCu, ArLi, or (S)-ArCu derivatives, respectively; ArHgOAc, ArHgCl, and (S)-ArHgOAc were obtained via the ligand exchange reactions between Ar2Hg and the respective HgX2 or between (S)-ArHgCl and AgOAc. They were identified by elemental analysis and XH and 13C NMR spectroscopy; molecular weight determinations indicated that they are monomeric in chloroform.…”