Stannylium Ions, a Tin(II) Arene Complex, and a Tin Dication Stabilized by Weakly Coordinating Anions

Abstract

The reactivity of aryl-substituted stannylenes, Ar(2)Sn (4), towards silylarenium borates, [R(3)SiArH][B(C(6)F(5))(4)] (3), was investigated. The reaction with 2,3,4-trimethyl-6-tert-butylphenyl (mebp)-substituted stannylene gave silyl-substituted stannylium ions 2a,b, which were characterized by NMR spectroscopy supported by the results of quantum-mechanical computations of molecular structures and magnetic properties. The tri-iso-propylphenyl-substituted stannylium ions 2c,d undergo a decomposition reaction in toluene to give the dicationic tin-arene complex [Sn(C(7)H(8))(3)](2+) (5) in the form of the [B(C(6)F(5))(4)] salt in high yields. The 5[B(C(6)F(5))(4)](2) salt was identified by single crystal X-ray diffraction analysis and by Mössbauer spectroscopy. The bonding situation was investigated by using natural bond orbital (NBO) and quantum theory of atoms in molecules (QTAIM) calculations. The substitution of the weakly coordinating borate anion by the carboranate [CB(11)H(6)Br(6)](-) results in replacement of the toluene ligands and formation of tin(II) carboranate with only weak Sn(2+)-anion interactions as suggested by the solid-state structure of the isolated salt.

Synthesis and structures of Cu-Cl-M adducts (M=Zn, Sn, Sb)

“…What is interesting about the anion/ cation relationship here, which is not seen in 1 (but is relevant to the antimony compound 7, below), is the orientation of the phenyl ring attached to P(2) [C(19)-C(24)] with respect to tin ( Figure 4). This ring sits above tin with Sn-C distances of 3.647(4)-4.043(4) Å and a Sn-ring centroid separation of 3.585 Å, distances that reflect a much weaker π-interaction than seen in examples where a more cationic tin is bonded to aromatic rings [usually, but not exclusively, solvent molecules (Probst et al, 1990) in [MX 4 ] -salts, M = B, X = C 6 F 5 (Schafer et al, 2011), M = Al, X = Cl (Rodesiler et al, 1975;Weininger et al, 1979;Schmidbaur et al, 1989aSchmidbaur et al, ,b,c, 1990bSchmidbaur et al, , 1991Frank, 1990a,b), M = Ga, X = Cl (Frank, 1990c)], where the Sn-ring centroid is ca. 2.6 Å.…”

Understanding the structure of salicyl hydrazone metallocomplexes: crystal structure, AIM and Hirshfeld surface analysis of trichloro-(N-salicylidenebenzoylhydrazinato-N,O,O′)-tin(IV)

“…Until now, the results of topological analysis of tincontaining compounds are limited to two hypothetical stannatranes [22], the complex [Sn(C 7 H 8 ) 3 ] 2+ dication [23], the low-coordinated tin Sn 2 (OCH 2 CH 2 NMe 2 )(OPh) dimer [20], hexacoordinated tin(IV) [24] and phenyl (triphenylstannyl)telluride [25,26]. According to the AIM theory, information on chemical bonding can be obtained analyzing the local minima, maxima, and saddle points of the electron density ρ(r) function.…”

Cations and dications of heavier group 14 elements in low oxidation states

“…75 Utilizing the same synthetic strategy, Driess et al prepared another remarkable chlorosilyliumylidene derivative 13 by the reaction of bidentate bis-NHC ligand with NHC·SiCl 2 (Scheme 9). 55 The 29 Si NMR resonances due to the three-coordinate Si nuclei in 12 + and 13 + were observed at δ= -3.3 and -58.4 ppm, 80 respectively. The upfield shift can also be attributed to the stronger electron donation from bis-NHC and iminophosphorane ligands.…”

“…20 These results kick-started the chemistry of low-valent Si(II) cations although 80 the existence of a mono-coordinated Si(II) cations has yet to be demonstrated.…”

“…32 75 Chart 2 Selective ligands used for stabilizing cations of heavier group 14 elements in low oxidation state. 80 Macrocyclic ligands like cryptands, crown ethers, azamacrocycles etc. have been noted for their remarkable metal complexation properties through numerous weak donor sites.…”