Synthesis and Mössbauer Spectroscopy of Formal Tin(II) Dichloride and Dihydride Species Supported by Lewis Acids and Bases

Abstract

(119)Sn Mössbauer spectroscopy was performed on a series of formal Sn(II) dichloride and dihydride adducts bound by either carbon- or phosphorus-based electron pair donors. Upon binding electron-withdrawing metal pentacarbonyl units to the tin centers in LB·SnCl2·M(CO)5 (LB = Lewis base; M = Cr or W), a significant decrease in isomer shift (IS) was noted relative to the unbound Sn(II) complexes, LB·SnCl2, consistent with removal of nonbonding s-electron density from tin upon forming Sn-M linkages (M = Cr and W). Interestingly, when the nature of the Lewis base in the series LB·SnCl2·W(CO)5 was altered, very little change in the IS values was noted, implying that the LB-Sn bonds were constructed with tin-based orbitals of large p-character (as supported by prior theoretical studies). In addition, variable temperature Mössbauer measurements were used to determine the mean displacement of the tin atoms in the solid state, a parameter that can be correlated with the degree of covalent bonding involving tin in these species.

Hydridoorganostannylene Coordination: Group 4 Metallocene Dichloride Reduction in Reaction with Organodihydridostannate Anions

“…[10c,d,f,k] The HfÀSn distances in 6 [2.770(1), 2.781(1) ]a re slightly longert han the bond length found in E (2.7585 (11) ). The HfÀSn bond lengths in hafnocene derivatives [CpCp*Hf(SnPh 3 )L], on the other hand, are significantly longer:L = Cl, 2.9650(4); NMe 2 ,2 .9694(8);M e, 2.9740(5); OMe, 2.9556 (5) . [17] The SnÀSn distances [4: 3.370(1), 5:3 .526(1), 6:3 .489(1) ]i nc omplexes 4-6 are longer than typical SnÀSn single bonds [Ar'H 2 Sn-SnH 2 Ar", 2.7449(3)] [Ar' = 2,6-Mes 2 C 6 H 3 ,M es = 2,4,6-trimethylphenyl],h owever short enough to point towards am inor interaction between both tin atoms.…”

“…Since Lappert et al invented the synthesis of germylenes and stannylenes in the early 1970s, the interaction of these Lewis basic and Lewis acidic molecules with transition metal fragments has been extensivelys tudied. [1] However,o ne of the first stannylene coordination compounds [Me 2 Sn(thf)Cr(CO) 5 ]w as already synthesized earlier,i n1 971, following as alt metathesis reactionb etween dimethyl tin dichloride and the dinuclear chromium carbonylate dianion [Cr 2 (CO) 10 ] 2À . [2] The coordination chemistry of diorgano-as well as diamidostannylenes became av ery attractive fieldo fr esearch and was further developed for av ariety of transitionm etal fragments.T he nature of the bondingb etween low valent Group 14 elements and transition metals was also studied intensively.D iamidostannylenes, for example, act as donorl igands, whereas dialkylstannylenes can also act as acceptor ligands, by providing an empty p-orbital.…”

“…[4] The coordination chemistry of low valent tin hydrides was investigated by Rivard et al for the highly reactive SnH 2 ,w hich was coordinated at transition metals to produce aL ewis base stabilized adduct. [5] Tilley et al reportedt he reactiono fa no smium benzyl complex with organotin trihydride tripSnH 3 (trip = 2,4, 6-triisopropylphenyl) to give an organohydridostannylene complex upon toluene elimination. [6] By reactinga nN HC adduct of al ow valent tin hydride [Ar*SnH( Me NHC)] with the platinum complex [Pt(cod) 2 ]adimeric tin-platinum complexf eaturing bridging hydride ligands was characterized at low temperature.…”

Interplay of donor–acceptor interactions in stabilizing boron nitride compounds: insights from theory

“…Specifically we examined the binding of the carbon-based donors, ImMe 2 (ImMe 2 = [(HCNMe) 2 C:]), ImMe 2 CH 2 and Me 3 PCH 2 to (BN) n units, given our use of their sterically hindered analogues to bind/stabilize inorganic methylene and ethylene units (EH 2 and H 2 EE 0 H 2 ; E and E 0 = Si, Ge and/or Sn). 14,[24][25][26][27][28][29][30][31] We also provide computations on LBÁ(BN) n ÁBH 3 and LBÁ(BN) n ÁW(CO) 5 adducts (n = 1-3) featuring coordinated (BN) n units and show that this overall donor-acceptor approach is a viable means of intercepting a complex of molecular boron nitride. Finally, based on detailed EDA-NOCV computations, we will comment on the strength and nature of both the carbene-boron and nitrogen-tungsten donor acceptor bonds in the ImMe 2 substituted BNÁW(CO) 5 and B 3 N 3 ÁW(CO) 5 adducts.…”

Donor–acceptor chemistry in the main group

“…39 ð7Þ In a collaboration with Prof. Rolfe Herber at the Racah Institute of Physics, the electron density and bonding properties within a series of Sn(II) halide and hydride adducts were interrogated via 119 Sn Mössbauer effect spectroscopy. 30 This technique provides a measure of the degree of s-electron density about a tin atom as this parameter can be directly correlated to the isomer shift (IS) value obtained (equal to the center of the doublet resonance); see Fig. 6 for a typical Mössbauer spectrum for one of our adducts, IPr•SnCl 2 (7).…”