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Metal complexes as ligands bi- and tri-nuclear complexes containing similar and dissimilar metal atoms
INORG. NUCL.
CHEM. LETTERS
Vel.
3,
pp.
495-499,
1967.
Pergame,
Press
Ltd.
Prleted
t,
Great Britain.
~ETAL COMPLEXES AS LIGANDS BI- AND TRI-NUCLEAR COMPLEXES CONTAINING SIMILAR AND DISSIMILAR METAL ATOMS S.J. Gruber, C.M. Harris and E. Sinn Department of Inorganic Chemistry, The University of New South Wales, Sydney, Australia (Received 3 August 1967)
New series of oxygen-bridge~ bi- and tri-nuclear complexes have been prepared by using metal salicylaldimine complexes as bidentate chelating agents. I This invokes the well established ability of the two-coordinate
oxygen atoms
in such compounds to raise their coordination number to three. 2
The idea was prompted by our studies 3 of antiferro-
magnetism in copper(ll)
complexes with such ligands as
pyridine- and quinoline-N-oxide, (o-hydroxyanil),
acetylacetone-mono-
and 8-hydroxyquinoline;
the hypothesis 3 that
magnetic properties of this type are explicable in terms of binuclear molecules involving three-coordinate
oxygen bridges
was confirmed by X-ray studies. 4
Schiff base
Tetradentate
(TSB) complexes of bivalent metals (M.TSB) have been used extensively I to form mono- and his-chelated complexes of the general type [(M.TSB)M'X 2] and [M'(M.TSB)2]Y2, unidentate
group such as a halogen,
where X is a
and Y an uncoordinated
anion such as Cl04-; M' is usually a bivalent metal such as Zn(II), Co(II) and Sr(II), though in some cases mono- and trivalent metals,
such as Ag(I) and Al(III) have been used.
is illustrated
(I - III) for TSB = 1,2-propylenebis(salicyl495
This
496
METAL COMPLEXES AS LIGAHDS
aldi~ine)
and M = i' - ~ .
Yel. 3, He. 11
Oe~plexee (I) and (II) aid ~hei~
HC--4~ /0 t
LU
3
)HC.~ ~ '2
(I)Peff/Cu ,,., 1.81B.M. (II)Peff/C~z ,,- 1.58EM. ( I I I ) ~ e f f / C ~ .
2H20
1.24B.]L
a n a l o g u e s w i t h o t h e r m e t a l s a~e n o n - i o n i c , w h i l e t h e complexes o f
~ype (Ill) are di-uni-valen~ electroly~es in ni~robenzene; quantitative analysis for each element p~esent, excep~ oxygen, for a large number of bi- and tri-nnclear complexes shows excellent agreement with ~he empirical formulae.
The me~al atoms
~re held together b y oxygen bridges rather than by metal-me~al bonds, and are sufficiently near each o~her to cause antiferrom~gue~ic interactions in many cases where both M and M' have unpaired electrons, as in the compounds (If) and (III), whose room t e m p e r a t e
magne%ic moments are below the spin-only value,
1.73 B.M. In the typical complexes dlchloro[N,N'-e~h~lenebls(salicylaldlmino)copper(II)]copper(II)
monohy~ate
(IV, Fig. I)
and his[N, N'-I, 3-propylenebis( sallcylal dimlno) copper(II) ]nlokel(II) perchlorate trlhydrate (V, Fig. 2), ~he strengths of the antiferromagne~Ic interactions are given b y the exchange in%e~als Jcu-Gu " -166 cm-I for compound (IV), and JCu-Ni " -61 cm-I and gCu-Cu " -5 cm-I for compound (V).
The behavion~
of compound (IV) is characteristic of many bim~clear copper compounds,3, 5 ~ d
a de~ailed ~eatment of the magnetic properties
METAL COMPLEXES AS LIGANDS
Vol. 3, No. 11
497
2OOC
'°~x"~ IOOC
,.s
(~
I-0
3OOO
I06Xlul /
,oo 200 T
300 400
o
,o
(~K)
I
Fig. Theoretical and experimental ~a~neti c properties for complex (IV) Cu-Cu.
of antiferro~gnetic
2oo
300 Too
T ['K)
Fig. 2 Theoretical and experimental ~ g n e t i c properties for complex (V) Ou-Ni-Cu
trinuolear complexes analogous to the
compound (V) h a s b e e n worked o u t and a p p l i e d t o compounds c o n talning a range of similar and dissimilar metals. 6 In contradiction
to our o b s e r v a t i o n s
complexes of the type [(M.TSB)M'X2]
on t h e above compounds,
obey a Curie-Welss law when
only one of the metal atoms, M or M', has unpaired electrons. Thus, the compounds dichloro[N, N'-ethylenebie(salicylaldimino)nickel(If) ]cobalt(ll)
and dichloro[N,N'-phenylenebis(salicyl-
aldimino)copper(ll)]mercury(ll)
have average m~g~uetic moments,
corrected for the Weiss constants, respectively.
of 4.92 ~ d
SinLilarly, appreciable
1.94 B.M.
antiferromagnetism
does not
occur in the trinuclear complexes when either the central metal M' or the terminal metal atoms M are diamagnetic:
the respect-
ive average corrected moments are 1.90 B.M./Cu and 5.83 B . M . / ~ for the complexes bisrN, N'-et~lenebis(salicylaldin~Ino) copper(ll)barium perchlorate and bls[N, N'-ethylenebis(salicylaldimino)-
498
METAL COMPLEXES AS LIGAHDS
nickel(II)]manganese(II)
Vol. 3, hlo. 11
perchlorate ~,ihydrate.
Bi- and tri-
n~clear complexes are necessarily diamagnetic when neither M nor M' has unpaired electrons,
as in dichloro[N,N'-e~hylenebis-
(salicylaldimino) zinc(If) ]zinc(II) monohydrate. We have also been able to use as ligands metal complexes of bidentate Schiff bases which are tetrahedral or sufficiently distorted from planar symmetry so that the two oxygen atoms are effectively cis to each other.
An example of this ~ype is
dibromo [bi s (N-t-butyl sali cyl al dimi no) cobalt (II ) ]cobalt (II ) dihydrate, which obeys a Curie-Weiss law between 80 and 400°K and possesses an average corrected moment of 4.77 B.M. It is easily seen that through the variety of accessible complexes,
a considerable range of stereochemistriee
can be
imposed on the metals M and M', and this coupled with the results of magnetic,
e.s.r., Mossbauer,
and spectral studies,
is expected to prove of considerable interest.
Moreover,
it has
proved possible to design specific compounds to test current theories of magnetism,
and many of the combinations of metals
have been studied for the first time, e.g. Cu-Ni-Cu in compound (V) (Fig. 2).
An X-ray crystallographic
examination of this
compound has been commenced here ~o test the hypothesis that the cu/Ni~ou
atoms lie at the corners of an isosceles triangle. References
I.
S.J. GRUBER, B.Sc.
(Honours) thesis (1963); Ph.D. thesis
(1966), The University of New South Wales. .
R.H. HOLM, G.W. EVERETT, JR., and A. CHAKRAVORTY, Complexes of Schiff Bases and ~-Ketosm~nes", Coordination Chemistry, and Sons, New York,
"Metal
Progress in
7, 83, Ed. F.A. Cotton, J. Wiley
1966, and references given.
Vol. 3, No. 11
3.
METAL COMPLEXES AS L|GAHDS
C.M. HARRIS, E. KOKOT, S.L. LENZER and T.N. LOCKYER, Chem. Ind., (London), 651 (1962); S.J. GRUBER, C.M. HARRIS, E. KOKOT, S.L. LENZER, T.N. LOCKYER, and E. SINN, Aust. J. Chem., in press; G.A. BARCLAY, C.M. HARRIS, B.F. HOSKINS, and E. KOKOT, Proc. Chem. Soc., 264 (1961); C.M. HARRIS, E. KOKOT and S.L. LENZER, Nature, 196, 471 (1962).
4.
G.A. BARCLAY and B.F. HOSKINS, J. Chem. Sot., 1979 (1965); H.L. SCHAFER, J.C. MORROW, and H.M. SMITH, J. Chem. Phys., 42, 504 (1965).
5.
M. KATO, H.B. JONASSON, and J.C. FANNING, Chem. Revs., 64, 99 (1964), and references given.
6.
S.J. GRU~R, C.M. HARRIS and E. SINN, to be published.
499
CHEM. LETTERS
Vel.
3,
pp.
495-499,
1967.
Pergame,
Press
Ltd.
Prleted
t,
Great Britain.
~ETAL COMPLEXES AS LIGANDS BI- AND TRI-NUCLEAR COMPLEXES CONTAINING SIMILAR AND DISSIMILAR METAL ATOMS S.J. Gruber, C.M. Harris and E. Sinn Department of Inorganic Chemistry, The University of New South Wales, Sydney, Australia (Received 3 August 1967)
New series of oxygen-bridge~ bi- and tri-nuclear complexes have been prepared by using metal salicylaldimine complexes as bidentate chelating agents. I This invokes the well established ability of the two-coordinate
oxygen atoms
in such compounds to raise their coordination number to three. 2
The idea was prompted by our studies 3 of antiferro-
magnetism in copper(ll)
complexes with such ligands as
pyridine- and quinoline-N-oxide, (o-hydroxyanil),
acetylacetone-mono-
and 8-hydroxyquinoline;
the hypothesis 3 that
magnetic properties of this type are explicable in terms of binuclear molecules involving three-coordinate
oxygen bridges
was confirmed by X-ray studies. 4
Schiff base
Tetradentate
(TSB) complexes of bivalent metals (M.TSB) have been used extensively I to form mono- and his-chelated complexes of the general type [(M.TSB)M'X 2] and [M'(M.TSB)2]Y2, unidentate
group such as a halogen,
where X is a
and Y an uncoordinated
anion such as Cl04-; M' is usually a bivalent metal such as Zn(II), Co(II) and Sr(II), though in some cases mono- and trivalent metals,
such as Ag(I) and Al(III) have been used.
is illustrated
(I - III) for TSB = 1,2-propylenebis(salicyl495
This
496
METAL COMPLEXES AS LIGAHDS
aldi~ine)
and M = i' - ~ .
Yel. 3, He. 11
Oe~plexee (I) and (II) aid ~hei~
HC--4~ /0 t
LU
3
)HC.~ ~ '2
(I)Peff/Cu ,,., 1.81B.M. (II)Peff/C~z ,,- 1.58EM. ( I I I ) ~ e f f / C ~ .
2H20
1.24B.]L
a n a l o g u e s w i t h o t h e r m e t a l s a~e n o n - i o n i c , w h i l e t h e complexes o f
~ype (Ill) are di-uni-valen~ electroly~es in ni~robenzene; quantitative analysis for each element p~esent, excep~ oxygen, for a large number of bi- and tri-nnclear complexes shows excellent agreement with ~he empirical formulae.
The me~al atoms
~re held together b y oxygen bridges rather than by metal-me~al bonds, and are sufficiently near each o~her to cause antiferrom~gue~ic interactions in many cases where both M and M' have unpaired electrons, as in the compounds (If) and (III), whose room t e m p e r a t e
magne%ic moments are below the spin-only value,
1.73 B.M. In the typical complexes dlchloro[N,N'-e~h~lenebls(salicylaldlmino)copper(II)]copper(II)
monohy~ate
(IV, Fig. I)
and his[N, N'-I, 3-propylenebis( sallcylal dimlno) copper(II) ]nlokel(II) perchlorate trlhydrate (V, Fig. 2), ~he strengths of the antiferromagne~Ic interactions are given b y the exchange in%e~als Jcu-Gu " -166 cm-I for compound (IV), and JCu-Ni " -61 cm-I and gCu-Cu " -5 cm-I for compound (V).
The behavion~
of compound (IV) is characteristic of many bim~clear copper compounds,3, 5 ~ d
a de~ailed ~eatment of the magnetic properties
METAL COMPLEXES AS LIGANDS
Vol. 3, No. 11
497
2OOC
'°~x"~ IOOC
,.s
(~
I-0
3OOO
I06Xlul /
,oo 200 T
300 400
o
,o
(~K)
I
Fig. Theoretical and experimental ~a~neti c properties for complex (IV) Cu-Cu.
of antiferro~gnetic
2oo
300 Too
T ['K)
Fig. 2 Theoretical and experimental ~ g n e t i c properties for complex (V) Ou-Ni-Cu
trinuolear complexes analogous to the
compound (V) h a s b e e n worked o u t and a p p l i e d t o compounds c o n talning a range of similar and dissimilar metals. 6 In contradiction
to our o b s e r v a t i o n s
complexes of the type [(M.TSB)M'X2]
on t h e above compounds,
obey a Curie-Welss law when
only one of the metal atoms, M or M', has unpaired electrons. Thus, the compounds dichloro[N, N'-ethylenebie(salicylaldimino)nickel(If) ]cobalt(ll)
and dichloro[N,N'-phenylenebis(salicyl-
aldimino)copper(ll)]mercury(ll)
have average m~g~uetic moments,
corrected for the Weiss constants, respectively.
of 4.92 ~ d
SinLilarly, appreciable
1.94 B.M.
antiferromagnetism
does not
occur in the trinuclear complexes when either the central metal M' or the terminal metal atoms M are diamagnetic:
the respect-
ive average corrected moments are 1.90 B.M./Cu and 5.83 B . M . / ~ for the complexes bisrN, N'-et~lenebis(salicylaldin~Ino) copper(ll)barium perchlorate and bls[N, N'-ethylenebis(salicylaldimino)-
498
METAL COMPLEXES AS LIGAHDS
nickel(II)]manganese(II)
Vol. 3, hlo. 11
perchlorate ~,ihydrate.
Bi- and tri-
n~clear complexes are necessarily diamagnetic when neither M nor M' has unpaired electrons,
as in dichloro[N,N'-e~hylenebis-
(salicylaldimino) zinc(If) ]zinc(II) monohydrate. We have also been able to use as ligands metal complexes of bidentate Schiff bases which are tetrahedral or sufficiently distorted from planar symmetry so that the two oxygen atoms are effectively cis to each other.
An example of this ~ype is
dibromo [bi s (N-t-butyl sali cyl al dimi no) cobalt (II ) ]cobalt (II ) dihydrate, which obeys a Curie-Weiss law between 80 and 400°K and possesses an average corrected moment of 4.77 B.M. It is easily seen that through the variety of accessible complexes,
a considerable range of stereochemistriee
can be
imposed on the metals M and M', and this coupled with the results of magnetic,
e.s.r., Mossbauer,
and spectral studies,
is expected to prove of considerable interest.
Moreover,
it has
proved possible to design specific compounds to test current theories of magnetism,
and many of the combinations of metals
have been studied for the first time, e.g. Cu-Ni-Cu in compound (V) (Fig. 2).
An X-ray crystallographic
examination of this
compound has been commenced here ~o test the hypothesis that the cu/Ni~ou
atoms lie at the corners of an isosceles triangle. References
I.
S.J. GRUBER, B.Sc.
(Honours) thesis (1963); Ph.D. thesis
(1966), The University of New South Wales. .
R.H. HOLM, G.W. EVERETT, JR., and A. CHAKRAVORTY, Complexes of Schiff Bases and ~-Ketosm~nes", Coordination Chemistry, and Sons, New York,
"Metal
Progress in
7, 83, Ed. F.A. Cotton, J. Wiley
1966, and references given.
Vol. 3, No. 11
3.
METAL COMPLEXES AS L|GAHDS
C.M. HARRIS, E. KOKOT, S.L. LENZER and T.N. LOCKYER, Chem. Ind., (London), 651 (1962); S.J. GRUBER, C.M. HARRIS, E. KOKOT, S.L. LENZER, T.N. LOCKYER, and E. SINN, Aust. J. Chem., in press; G.A. BARCLAY, C.M. HARRIS, B.F. HOSKINS, and E. KOKOT, Proc. Chem. Soc., 264 (1961); C.M. HARRIS, E. KOKOT and S.L. LENZER, Nature, 196, 471 (1962).
4.
G.A. BARCLAY and B.F. HOSKINS, J. Chem. Sot., 1979 (1965); H.L. SCHAFER, J.C. MORROW, and H.M. SMITH, J. Chem. Phys., 42, 504 (1965).
5.
M. KATO, H.B. JONASSON, and J.C. FANNING, Chem. Revs., 64, 99 (1964), and references given.
6.
S.J. GRU~R, C.M. HARRIS and E. SINN, to be published.
499