Structure and magnetic behaviour of [{Mn-2(3-Et,4-Mepy)(6)(mu(1,1)-N-3)(2)(mu(1,3)-N-3)}(n)][PF6](n) and [{Mn-2(3-ampy)(4)(mu(1,1)-N-3)(2)(mu(1,3)-N-3)(N-3)(H2O)center dot 4H(2)O}(n)], two alternating ferro-antiferromagneticone-dimensional compounds

TTwo new monodimensional compounds, [{Mn-2(3-Et,4-Mepy)(6)(mu(1,1)-N-3)(2)( mu(1,3)-N-3)}(n)][PF6](n) 1 and [{Mn-2(3-ampy)(4)( mu(1,1)-N-3)(2)(mu(1,3)- N-3)(N-3)(H2O). 4H(2)O}(n)] 2 in which 3-Et,4-Mepy = 3-ethyl-4-methylpyridi ne; 3-ampy = 3-aminopyridine, have been synthesised and studied from the ma gnetostructural point of view. Compounds 1 and 2 are one-dimensional compou nds which show [Mn(mu(1,1)-N-3)(2)Mn](2+) dimeric entities linked to the tw o neighbours by one end-to-end azido bridge, leading to alternate ferro-ant iferromagnetic monodimensional manganese(II) azido compounds. Compounds 1 a nd 2 are bulk antiferromagnetically coupled systems. The best t superexchan ge parameters are: J(1) = 3.3(1) cm(-1), J(2) = -5.16(1) cm(-1), g = 2.00(1 ) for 1 and J(1) = 2.3(2) cm(-1), J(2) = -6.01(3) cm(-1), g = 2.07(1) for 2 .