Syntheses and Molecular Structures of [RSn{W(CO)3Cp}2][W(CO)3Cp], [RSn{W(CO)3Cp}Cl2], and [RSn{W(CO)3Cp}Cr(CO)5] (R = [4-t-Bu-2,6-{P(O)(OR′)2}2C6H2], R′ = Et, i-Pr). Autoionization Induced by Intramolecular P═O→Sn Coordination

Intramolecularly O,N,O-Coordinated Tin(II) Salts: Syntheses, Structures, Cyclization, and Transition Metal Complexation

We report the syntheses of tin(II) salts of the types [L1SnX]SnX3 [L1=2,6-{(i-PrO)2(O)P}2C5H3N: 1, X=Cl; 2, X=Br], [L2SnCl]SnCl3 [L2=2-{(i-PrO)Ph(O)P}-6-{(i-PrO)2(O)P}C5H3N: 3], [L3SnX]SnX3 [L3=2,6-{MeO(O)C}2C5H3N: 4, X=Cl; 5, X=Br], [L4SnX]SnX3 [L4=2,6-{Et2N(O)C}2C5H3N: 6, X=Cl; 7, X=Br]. These compounds were obtained by addition of SnX2 to the corresponding ligand inducing autoionization of the respective tin(II) halide. The thermal stability of 1, 3, and 4 was elucidated, giving, under ester cleavage and cyclisation, the tin(II) derivatives 8-12. The reaction of [L1SnCl]SnCl3 (1) with W(CO)4(thf)2 afforded the tungsten tetracarbonyl complex [{L1SnCl}{SnCl3}W(CO)4] (13), representing the first example in which a tin(II) stannate anion and a tin(II) stannylium cation simultaneously coordinate to a transition metal centre. The compounds were characterized by single crystal X-ray diffraction analyses and in part by elemental analyses, IR and NMR spectroscopy, electrospray ionization mass spectrometry. DFT calculations accompany the experimental work.

N-Functionalized Ferrocenes: Subvalent Group XIV Element Chlorides and tert-Butyllithium-Induced C-C Bond Cleavage under Mild Conditions

The ferrocene derivative (η⁵ -Cp)Fe{η⁵ -C₅ H₃ -1-(ArNCH)-2-(CH₂ NMe₂ )} (1; Ar=2,6-iPr₂ C₆ H₃ )) reacts diastereoselectively with LiR by carbolithiation and subsequent hydrolysis to give (η⁵ -Cp)Fe{η⁵ -C₅ H₃ -1-(ArHNCHR)-2-(CH₂ NMe₂ )} (3: R=tBu; 4: R=Ph; 5: R=Me) in high yields. For R=tBu, the organolithium derivative (η⁵ -Cp)Fe{η⁵ -C₅ H₃ -1-(ArLiNCHR)-2-(CH₂ NMe₂ )} (2) was isolated. Compound 2 reacts with GeCl₂ ⋅dioxane and SnCl₂ to give the metallylene amide chlorides (η⁵ -Cp)Fe{η⁵ -C₅ H₃ -1-(ArMNCHtBu)-2-(CH₂ NMe₂ )} 6 (M=GeCl) and 7 (M=SnCl), respectively, which each contain three stereogenic centers. The potential of 7 as a ligand in transition-metal chemistry is demonstrated by formation of its complex (η⁵ -Cp)Fe{η⁵ -C₅ H₃ -1-(ArMNCHtBu)-2-(CH₂ NMe₂ )} [9, M= Sn(Cl)W(CO)₅ ]. Treatment of 3 with tert-butyllithium at room temperature causes an unprecedented carbon-carbon bond cleavage whereas under kinetic control, lithiation at the Cp-3 position takes place, which leads to the isolation of (η⁵ -Cp)Fe{η⁵ -C₅ H₃ -1-(ArHNCHtBu)-2-(CH₂ NMe₂ )-3-SiMe₃ } (10).

A Ferrocenyl-Backboned Unsymmetric O,C-Coordinating Ligand and Its Tin Derivatives

The syntheses of the phosphonyl-substituted ferrocenyl stannane Fe[{η (5)-C5H3-1-SnPh3-2-P(O)(O-iPr)2}{η (5)-C5H4P(O)(O-iPr)2}] (1) and its iodine derivative Fe[{η (5)-C5H3-1-SnPh2I-2-P(O)(O-iPr)2}{η (5)-C5H4P(O)(O-iPr)2}] (2) are reported. The syntheses of the corresponding salts Fe[{η (5)-C5H3-1-SnPh2-2-P(O)(O-iPr)2}{η (5)-C5H4P(O)(O-iPr)2}]X (3, X=Al{OC(CF3)3}4, 4, X=ClO4, 5, X=HgI3), respectively, are also described. The compounds are characterized by elemental analyses, (1)H, (13)C, (31)P, (119)Sn NMR and IR spectroscopy, electrospray ionization mass spectrometry, and, except for 4 and 5, single-crystal X-ray diffraction analyses.

Reactive p-block cations stabilized by weakly coordinating anions

The chemistry of the p-block elements is a huge playground for fundamental and applied work. With their bonding from electron deficient to hypercoordinate and formally hypervalent, the p-block elements represent an area to find terra incognita. Often, the formation of cations that contain p-block elements as central ingredient is desired, for example to make a compound more Lewis acidic for an application or simply to prove an idea. This review has collected the reactive p-block cations (rPBC) with a comprehensive focus on those that have been published since the year 2000, but including the milestones and key citations of earlier work. We include an overview on the weakly coordinating anions (WCAs) used to stabilize the rPBC and give an overview to WCA selection, ionization strategies for rPBC-formation and finally list the rPBC ordered in their respective group from 13 to 18. However, typical, often more organic ion classes that constitute for example ionic liquids (imidazolium, ammonium, etc.) were omitted, as were those that do not fulfill the - naturally subjective -"reactive"-criterion of the rPBC. As a rule, we only included rPBC with crystal structure and only rarely refer to important cations published without crystal structure. This collection is intended for those who are simply interested what has been done or what is possible, as well as those who seek advice on preparative issues, up to people having a certain application in mind, where the knowledge on the existence of a rPBC that might play a role as an intermediate or active center may be useful.

Syntheses, structures and anti-tumor activity of four new organotin(iv) carboxylates based on 2-thienylselenoacetic acid

With the 2-thienylselenoacetic acid ligand, four new organotin complexes have been synthesized and characterized by X-ray crystallography, elemental analysis, FT-IR and NMR (¹H,¹³C, and¹¹⁹Sn) spectroscopy.

Supramolecular assemblies of organotin(iv)–diphosphoryl adducts: insights from X-rays and DFT

The influence of tin-bonded substituents on the organization of the crystal structures and also coordination interactions were discussed using geometrical parameters, Hirshfeld analysis and theoretical calculations.