Trinuclear complexes of general formulas [ MC~,(CH,C0,),(salpd)~] (M = Mgll, Mn", Co", Ni", Cull, or Zn") and [MNi,(CH,CO,),(salpd),] (M = Mgll, Mn", Co", or Ni") were prepared, where H,salpd represents propene-l,3-diylbis(salicylideneimine). Further reactions of the complexes of the former series with sulphur dioxide yielded [MCu2(CH,C0,S0,),(saIpd),] (M = Mgll, Mn", Co", or Ni") and [Cu,( HSO,),(salpd),( H,O),]. Cryomagnetic measurements (77.4-295 K) have shown that a weak or negligible antiferromagnetic spin coupling ( J = -46 t o 0 cm-') is operating between the terminal and central metal ions in the complexes except for [Cu,( HSO,) (salpd),( H,O),] which showed a strong antiferromagnetic coupling ( J = -1 86 cm-') between neighbouring copper(ii) ions. X-Ray crystal analysis was carried out for [Zn{(p-CH,CO,) (salpd-p-O,O')Cu),]. It crystallizes in the monoclinic space group P2Ja with a = 16.228(5), b = 11.971 (2), c = 9.239(3)A, p = 100.1 5(3)", Z = 2, and R = -0.0887. The complex consists of a linear Cu"--Zn"-Cu" trinuclear unit which has an inversion centre. The Cull and Zn" are bridged by the two phenolate oxygens of the salpd and the oxygens of the acetate ion.

The title complexes have been synthesized in quantitative yield from [Cu(salpd)] and copper(II) acetate or copper(II) formate , where H2salpd represents N,N′-disalicylidene-1,3-propanediamine. [Cu(salpd-μ-O,O′)(μ-L)Cu(μ-CH3O)2Cu(μ-L)(salpd-μ-O,O′)Cu] crystallizes in the monoclinic space group P21/n with formula=Cu4C40H44N4O10, F.W.=995.0, a=11.826(2) Å, b=17.192(4) Å, c=9.836(2) Å, β=94.08(2)°, V=1994.8(7) Å3 and Z=2 (R=3.83%), where L=CH3COO. The complex forms a centrosymmetric molecule made up of two units of [Cu(salpd-μ-O,O′)(μ-CH3COO)Cu] bound by a pair of methoxo bridges; each terminal copper(II) ion forms four short bonds with N and O atoms of salpd and a slightly longer (2.235(4) Å) axial bond with one of the oxygens of the acetato group, whereas each inner copper(II) ion is also pyramidally coordinated by two methoxo oxygens, one of the acetato oxygens, and one of the bridging salpd oxygens, the distant axial position being occupied (Cu–O=2.323(3) Å) by the remaining bridging salpd oxygen. The magnetic susceptibilities of the complexes in the 86.8–299.0 K range have been analyzed on the basis of a four-spin model for the linear copper(II) complexes, and the values of g and Jij, based on the Heisenberg-type Hamiltonian H=−2ΣJijSi·Sj, have been estimated as g (average)=2.13, J12=−390 cm−1, J13=67 cm−1 and J14=34 cm−1 in the complex with acetate bridges, and as g (average)=2.20, J12=−263 cm−1, and J13=39 cm−1 and J14=J34=0 cm−1 in the complex with formate bridges, where the numbering refers to the 3–1–2–4 arrangement of the Cu2+ ions.

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