Whe
n the cyclic bis(ami
no)sta
nnyle
neMe
2Si(NtBu)
2S
n is allowed to reactwith metal halides MX
2 (M = Cr, Fe,Co, Z
n; X = Cl, Br [Z
n]) adducts of the ge
neral formu
la[Me
2Si(NtBu)
2S
n·MX
2]
nare obtai
ned. The compou
ndsare ge
nerally dimeric (
n = 2) except the Z
nBr
2 adduct,which is mo
nomeric i
n be
nze
ne. The crystal structuresof[Me
2Si(NtBu)
2S
n·CoCl
2]
2(tricli
nic, space group
ntities/Pmacr.gif">1;
a =8.620(9) &Ari
ng;,
b = 9.160(9) &Ari
ng;,
c =12.280(9) &Ari
ng;,
![](/images/gifchars/alpha.gif)
=101.2(1)
![](/images/e<font color=)
ntities/deg.gif">,
![](/images/gifchars/beta2.gif)
= 97.6(1)
![](/images/e<font color=)
ntities/deg.gif">,
![](/images/gifchars/gamma.gif)
= 105.9(1)
![](/images/e<font color=)
ntities/deg.gif">, Z= 1) a
nd of[Me
2Si(NtBu)
2S
n·Z
nCl
2]
2(mo
nocli
nic, space group
P2
1/
c;
a = 8.156(9) &Ari
ng;,
b = 16.835(12) &Ari
ng;,
c = 13.206(9) &Ari
ng;,
![](/images/gifchars/beta2.gif)
= 94.27(6)
![](/images/e<font color=)
ntities/deg.gif">,
Z = 2) were determi
ned by X-ray diffractio
ntech
niques. The two compou
nds form simi
lar polycyclic,ce
ntrosymmetrical assemblies of metal atoms bridgedby chlori
ne or
nitroge
n atoms. While i
n the case of the cobaltcompou
nd Co is pe
ntacoordi
nated by three chlori
nea
nd two
nitroge
n atoms, i
n the zi
nc deri
vati
ve Z
n is almosttetrahedrally coordi
nated by three chlori
ne atoms a
ndo
ne
nitroge
n atom. The iro
n deri
vati
ve[Me
2Si(NtBu)
2S
n·FeCl
2]
2seems to be isostructural with the cobaltcompou
nd as ca
n be deduced from the crystal data (tricli
nic,
a = 8.622(7) &Ari
ng;,
b = 9.158(8) &Ari
ng;,
c = 12.353(8) &Ari
ng;,
![](/images/gifchars/alpha.gif)
= 101.8(1)
![](/images/e<font color=)
ntities/deg.gif">,
![](/images/gifchars/beta2.gif)
= 96.9(1)
![](/images/e<font color=)
ntities/deg.gif">,
![](/images/gifchars/gamma.gif)
=105.9(1)
![](/images/e<font color=)
ntities/deg.gif">,
Z = 1). If NiBr
2,PdCl
2, or PtCl
2 is combi
ned with thesta
nnyle
ne,the reactio
n product is totally differe
nt: 4 equi
v of the sta
nnyle
neare coordi
nati
ng per metal halide, formi
ng themolecu
lar compou
nd[Me
2Si(NtBu)
2S
n]
4MX
2,which crystallizes with half a mole of be
nze
ne per molecu
larformu
la.The crystal structures of[Me
2Si(NtBu)
2S
n]
4·NiBr
2·
1/
2C
6H
6(tetrago
nal, space group
I4
1/
a,
a =
b = 43.86(4) &Ari
ng;,
c = 14.32(2) &Ari
ng;,
Z = 16) a
nd[Me
2Si(NtBu)
2S
n]
4·PdCl
2·
1/
2C
6H
6(tetrago
nal, space group
I4
1/
a,
a =
b = 43.99(4)&Ari
ng;,
c = 14.318(14) &Ari
ng;,
Z = 16) re
vealthe two compou
nds to be isostructural. The molecules ha
ve a
n i
nnerS
n4Mpe
ntametallic core (mea
n dista
nces: S
n-Ni 2.463 &Ari
ng;, S
n-Pd 2.544&Ari
ng;) with the tra
nsitio
n metal i
n the ce
nter ofa slightly distorted square formed by the four ti
n atoms, thedistortio
n from p
lanarity resulti
ng i
n a weakparamag
netism of 0.2
![](/images/e<font color=)
ntities/mgr.gif">
B for the
nickel compou
nd. Thehaloge
n atoms form bridges betwee
n two of the ti
natoms a
nd ha
ve
no bo
ndi
ng i
nteractio
n with the tra
nsitio
n metal.The
nickel compou
nd has also bee
n preparedby direct i
nteractio
n of Br
2 orNR
4Br
3 with[Me
2Si(NtBu)
2S
n]
4Ni asa mi
nor product, the mai
n products bei
ngMe
2Si(NtBu)
2S
n(NtBu)
2SiMe
2,Me
2Si(NtBu)
2S
nBr
2,NiBr
2 a
nd S
nBr
2. Other metal clusters ha
vebee
n obtai
nedby the reactio
n of Me
2Si(NtBu)
2S
nwith tetrakis(triphe
nyphosphi
ne)pal
ladium or by the reactio
nof Me
2Si(NtBu)
2Gewith RhCl(PPh
3)
3. I
n the first casePh
3PPd[S
n(NtBu)
2SiMe
2]
3PdPPh
3(rhombohedral, space group
R3
c,
a =
b =21.
397(12) &Ari
ng;,
c = 57.01(5) &Ari
ng;,
![](/images/gifchars/alpha.gif)
=
![](/images/gifchars/beta2.gif)
=90
![](/images/e<font color=)
ntities/deg.gif">,
![](/images/gifchars/gamma.gif)
= 120
![](/images/e<font color=)
ntities/deg.gif">,
Z = 12) is formed a
nd ischaracterized by X-ray tech
niquesto be composed of a ce
ntral PdS
n3Pd trigo
nal bipyramidwith the ti
n atoms occupyi
ng the equatorial positio
ns(Pd-S
n = 2.702(5) &Ari
ng;). I
n the seco
nd reactio
n all thetriphe
nylphosphi
ne liga
nds are rep
laced from rhodium a
ndRh[Ge(NtBu)
2SiMe
2]
4Clis formed (mo
nocli
nic, space group
P2
1/
n,
a =12.164(2) &Ari
ng;,
b = 23.625(5) &Ari
ng;,
c=24.128(5) &Ari
ng;,
![](/images/gifchars/beta2.gif)
= 102.74(3)
![](/images/e<font color=)
ntities/deg.gif">,
Z = 4).The ce
ntral core of
this molecule is made up of a rhodium atomwhich isalmost square p
lanarly coordi
nated by the germa
nium atoms, two of whichare bridged by chlori
ne (mea
n Ge-Rh = 2.355 &Ari
ng;).