The Mössbauer effect in tin(II) compounds. Part X. Insertion reactions of tin(II) compounds with carbonyl-π-cyclopentadienyliron derivatives

Abstract

The products of the insertion reactions of a number of tin(ll) compounds SnXa (X = Cl. Br, 1, NCS, HCOa, and AcO) with [(w-C,H,)Fe(CO),],and (w-C,H,) Fe(CO.J,CI are compared with those from replacement of CI from [(n-C5H6) Fe(CO),],*SnCI, and (n-C,H,) Fe(CO),SnCI,.The llaSn Mossbauer parameters of both series of compounds [(n-C6HB)Fe(C0)2]2*SnX2 and (w-C6H5)Fe(CO),*SnX3 (X = CI, Br, I, NCS, HCO,, and AcO) show that the use of tin bonding electrons is dominated by the Sn-Fe bond. The trends in chemical isomer shift and quadrupole splitting can be explained with reference to the very short Sn-Fe bond lengths in these materials.The positive sign for e29Q can also be explained in terms of a high p-electron density on the tin atom in the direction of the Sn-Fe bond. The i.r. for the products of the insertion reactions are also presented. SEVERAL x-cyclopentadienyl iron carbonyl complexes containing the tin-iron bond have been prepared and compounds of the type (X-C~H~)F~(CO),*S~R, (R = Cl,,+ Br,3s5 I,q5 Me? Et,, and Ph2*) and [(x-C5Hs)-Fe(CO)d,*SnR1, (R1 = C1,3j6 Br? I,8 Me: Et,&' Ph,7 NCS,7,8 AcO,' SEt,' C5H5,7 OH,'have been reported. Some of these complexes can be prepared from either tin@) 3,5s6 or tin(1v) 2,3,7 starting materials and there is apparently no difference in the nature of the products from the two types of re: action.The crystal structures of the following compounds are known: (x-CsHs)Fe(CO),*SnR, (R = Cl,9 Br,s or Ph lo) and [(x-CsHs)Fe(CO)J3*SnR', (R' = Cl, ' C5H,,12 and NO, 14). In each case the tin atom is in a distorted tetrahedral environment in which the bonds to the iron atoms are very short (2-46-2-60 A) while those to the ligands are longer than the sums of the appropriate covalent radii. The bond angles in the tin environment are severely distorted from the ideal tetrahedral angles. These features can be explainedll in terms of an increase in the s-character of the tin orbitals used in the tin-iron bond formation with a corresponding increase in the p-character of the orbitals forming the other bonds with tin. Bryan and his co-workers have pointed out that in the (x-C,H,)Fe(CO),*SnX, complexes, the two halide moieties (-SnC1, and -SnBr,), differ in their conformations about the Sn-Fe bond axis and also differ in this respect from both of the conformationally independent molecules in the unit cell of (x-C,H,)Fe-(CO),*SnPh,. They interpret these differences as being a strong indication of free rotation about the metalmetal bond. This and the values of the Sn-Fe distances

Chemical Bonding in Compounds of the CuAl2 Family: MnSn2, FeSn2 and CoSn2

“…For a FeÀSn interaction, the only spectroscopic data available is for (p-C 5 H 5 )(CO) 2 Fe À SnCl 3 . [73] From the vibrational frequency of 222 cm…”

Synthesis and structural characterisation of the complex mer-[{Rh(CNC8H9)3(SnCl3)(µ-SnCl2)}2]

“…{ R h(CNC, H , ) , (SnCl 3)(p-SnCl,)) ,] were deposited rapidly.The mixture was stirred for 30 min, filtered and the green solid washed with acetone, dichloromethane and finally diethyl ether and dried in vacuo (0.1750 g, 71%) (Found: C,35.40; H, 2.90; C1, 19.40; N, 4.60. CS4Hs4Cll,N,Rh2Sn, requires C, 35.60; H, 3.00; C1, 19.45; N, 4.60%).…”