When the cyclic bis(amino)stannyleneMe
2Si(NtBu)
2Sn is allowed to reactwith metal halides MX
2 (M = Cr, Fe,Co, Zn; X = Cl, Br [Zn]) adducts of the general formula[Me
2Si(NtBu)
2Sn·MX
2]
nare obtained. The compoundsare generally dimeric (n = 2) except the ZnBr
2 adduct,which is monomeric in benzene. The crystal structuresof[Me
2Si(NtBu)
2Sn·CoCl
2]
2(triclinic, space group
![](/images/entities/Pmacr.gif)
1;
a =8.620(9) Å,
b = 9.160(9) Å,
c =12.280(9) Å,
![](/images/gifchars/alpha.gif)
=101.2(1)
![](/images/entities/deg.gif)
,
![](/images/gifchars/beta2.gif)
= 97.6(1)
![](/images/entities/deg.gif)
,
![](/images/gifchars/gamma.gif)
= 105.9(1)
![](/images/entities/deg.gif)
, Z= 1) and of[Me
2Si(NtBu)
2Sn·ZnCl
2]
2(monoclinic, space group
P2
1/
c;
a = 8.156(9) Å,
b = 16.835(12) Å,
c = 13.206(9) Å,
![](/images/gifchars/beta2.gif)
= 94.27(6)
![](/images/entities/deg.gif)
,
Z = 2) were determined by X-ray diffractiontechniques. The two compounds form similar polycyclic,centrosymmetrical assemblies of metal atoms bridgedby chlorine or nitrogen atoms. While in the case of the cobaltcompound Co is pentacoordinated by three chlorineand two nitrogen atoms, in the zinc derivative Zn is almosttetrahedrally coordinated by three chlorine atoms andone nitrogen atom. The iron derivative[Me
2Si(NtBu)
2Sn·FeCl
2]
2seems to be isostructural with the cobaltcompound as can be deduced from the crystal data (triclinic,
a = 8.622(7) Å,
b = 9.158(8) Å,
c = 12.353(8) Å,
![](/images/gifchars/alpha.gif)
= 101.8(1)
![](/images/entities/deg.gif)
,
![](/images/gifchars/beta2.gif)
= 96.9(1)
![](/images/entities/deg.gif)
,
![](/images/gifchars/gamma.gif)
=105.9(1)
![](/images/entities/deg.gif)
,
Z = 1). If NiBr
2,PdCl
2, or PtCl
2 is combined with thestannylene,the reaction product is totally different: 4 equiv of the stannyleneare coordinating per metal halide, forming themolecular compound[Me
2Si(NtBu)
2Sn]
4MX
2,which crystallizes with half a mole of benzene per molecularformula.The crystal structures of[Me
2Si(NtBu)
2Sn]
4·NiBr
2·
1/
2C
6H
6(tetragonal, space group
I4
1/
a,
a =
b = 43.86(4) Å,
c = 14.32(2) Å,
Z = 16) and[Me
2Si(NtBu)
2Sn]
4·PdCl
2·
1/
2C
6H
6(tetragonal, space group
I4
1/
a,
a =
b = 43.99(4)Å,
c = 14.318(14) Å,
Z = 16) revealthe two compounds to be isostructural. The molecules have an innerSn
4Mpentametallic core (mean distances: Sn-Ni 2.463 Å, Sn-Pd 2.544Å) with the transition metal in the center ofa slightly distorted square formed by the four tin atoms, thedistortion from planarity resulting in a weakparamagnetism of 0.2
B for the nickel compound. Thehalogen atoms form bridges between two of the tinatoms and have no bonding interaction with the transition metal.The nickel compound has also been preparedby direct interaction of Br
2 orNR
4Br
3 with[Me
2Si(NtBu)
2Sn]
4Ni asa minor product, the main products beingMe
2Si(NtBu)
2Sn(NtBu)
2SiMe
2,Me
2Si(NtBu)
2SnBr
2,NiBr
2 and SnBr
2. Other metal clusters havebeen obtainedby the reaction of Me
2Si(NtBu)
2Snwith tetrakis(triphenyphosphine)palladium or by the reactionof Me
2Si(NtBu)
2Gewith RhCl(PPh
3)
3. In the first casePh
3PPd[Sn(NtBu)
2SiMe
2]
3PdPPh
3(rhombohedral, space group
R3
c,
a =
b =21.397(12) Å,
c = 57.01(5) Å,
![](/images/gifchars/alpha.gif)
=
![](/images/gifchars/beta2.gif)
=90
![](/images/entities/deg.gif)
,
![](/images/gifchars/gamma.gif)
= 120
![](/images/entities/deg.gif)
,
Z = 12) is formed and ischaracterized by X-ray techniquesto be composed of a central PdSn
3Pd trigonal bipyramidwith the tin atoms occupying the equatorial positions(Pd-Sn = 2.702(5) Å). In the second reaction all thetriphenylphosphine ligands are replaced from rhodium andRh[Ge(NtBu)
2SiMe
2]
4Clis formed (monoclinic, space group
P2
1/
n,
a =12.164(2) Å,
b = 23.625(5) Å,
c=24.128(5) Å,
![](/images/gifchars/beta2.gif)
= 102.74(3)
![](/images/entities/deg.gif)
,
Z = 4).The central core of this molecule is made up of a rhodium atomwhich isalmost square planarly coordinated by the germanium atoms, two of whichare bridged by chlorine (mean Ge-Rh = 2.355 Å).