Synthese und Festkörperstruktur des Koordinationspolymers {Zn[Sn(CH₂SMe)₄]_0.5Cl₂}_n

Abstract

The tin compounds Sn(CH 2 SMe) 4 and Sn(CH 2 PPh 2 ) 4 are accessible from reaction of SnCl 4 with LiCH 2 SMe and LiCH 2 PPh 2 , respectively. X-ray quality crystals of Sn(CH 2 PPh 2 ) 4 (tetragonal, P42c) are obtained from a benzene solution at 4°C. The lithium methanide [Li(PMDTA)CH 2 PPh 2 ], which was a starting material in the synthesis of Sn(CH 2 PPh 2 ) 4 crystallized from a mixture of diethyl ether and pentane at Ϫ20°C in the monoclinic space group P2 1 /c. The coordination polymer {Zn[Sn(CH 2 SMe) 4 ] 0.5 Cl 2 } n was Einleitung

Chemical behavior of ortho-hydroquinone-based bis(pyrazol-1-yl)methane ligands in the presence of palladium(II) chloride

“…3, Table 1) were obtained by slow evaporation of a saturated chloroform solution. As already evidenced by the spectroscopic data, 1(H) consists of a bis(pyrazol-1-yl)methane moiety and an orthohydroquinone unit with CeO-bond lengths of 1.372(6) A and 1.378(7) A, which compare favorably to the bond lengths in the corresponding para-hydroquinone system (2,5-(OH) 2 C 6 H 3 CH(pz) 2 (4) ), which is close to the perfect tetrahedral angle. As is common for bis(pyrazol-1-yl) methane moieties the pyrazole donors adopt a conformation in which the nitrogen lone pairs point away from each other.…”

“…Thus the question arises as to what are the factors leading to decomposition. A marked difference between Ph 2 C(3-tBupz) 2 and 1(tBu) is obviously the hydroxyl substitution pattern of the latter. These oxygen atoms can exert two influences: (i) Mesomeric stabilization of a positive (partial) charge at the bis(pyrazol-1-yl) methane carbon atom by the para-hydroxyl group.…”

“…The most significant difference is observed for the C1eC21 bond between the bis(pyrazol-1-yl)methane fragment and the ortho-hydroquinone moiety, which is slightly elongated (1.522(4) A) compared to the length of 1.504(8) A of 1 (H). When also considering the substituted para-hydroquinonyl bis(pyrazol-1-yl)methanes (2,5-(OCH 3 ) 2 -C 6 H 3 CH(3-Mepz) 2 1.513 (2) The Pd(II) complex 2(H) crystallizes from a saturated THF solution by layering with hexane in the monoclinic space group P2 1 /n (Fig. 5).…”

“…Multidentate ligand systems have attracted considerable interest in the last decades [1,2]. Prominent examples of this class of ligands are the (pyrazol-1-yl)borates (scorpionates) [R n Bpz 4Àn ] À (R ¼ H, alkyl, aryl; n ¼ 2, 1, 0; pz ¼ pyrazol-1-yl) [3e5] and the (2-methimazol-1-yl)borates [R n Bmt 4Àn ] À (R ¼ H, alkyl, aryl; n ¼ 2, 1, 0; mt ¼ 2-methimazol-1-yl) [6e8].…”

Donor‐unsupported Phosphanylmethanides Li[CH2PR2] (R = tBu, Ph) – Crystal Structure of Li[CH2PtBu2] Solved by XRPD and DFT‐D Calculations

“…Despite the long existence and common usage of phosphanyl‐substituted lithium organyls,6–9 the molecular structures of the solvent‐free lithium compounds Li[CH 2 P R 2 ] ( R = t Bu, Ph) have not yet been investigated. However, the structures of the donor‐supported lithium methanides Li(D) n [CH 2 PPh 2 ] [D = N,N,N′,N′′,N′′‐pentamethyldiethylenetriamine (pmdta; n = 1),10 N,N,N′,N′‐tetramethylethylenediamine (tmeda; n = 1),11,12 dioxane; n = 1.75]13 have been subject to studies in recent years. In the presence of tridentate pmdta, diphenylphosphanylmethyllithium was found to exist as discrete monomers Li(pmdta)[CH 2 PPh 2 ] in the solid state (Figure 1).…”