Nine Diiron(II) Complexes of Three Bis-tetradentate Pyrimidine Based Ligands with NCE (E = S, Se, BH3) Coligands

作者：Gobeze Worku A; Milway Victoria A; Olguin Juan; Jameson Guy N L; Brooker Sally^*

来源：Inorganic Chemistry, 2012, 51(16): 9056-9065.

DOI：10.1021/ic3012052

Three bis-tetradentate acyclic amine ligands differing only in the arm length of the pyridine pendant arms attached to the 4,6-positions of the pyrimidine ring, namely, 4,6-bis[N,N-bis(2%26apos;-pyridylethyl)aminomethyl]-2-phenylpyrimidine (L-Et), 4,6-bis[N,N-bis(2%26apos;-pyridylmethyl)aminomethyl]-2-phenylpyrimidine (L-Me), and 4,6-[(2%26apos;-pyridylmethyl)-2%26apos;-pyridylethyl)aminomethyl]-2-phenylpyrimidine (L-Mix) have been used to synthesize nine air-sensitive diiron(II) complexes: [(Fe2LEt)-L-II(NCS)(4)]center dot MeOH center dot 3/4H(2)O (1 center dot MeOH center dot 3/4H(2)O), [(Fe2LEt)-L-II(NCSe)(4)]center dot H2O (2 center dot H2O), [(Fe2LEt)-L-II(NCBH3)(4)]center dot 5/2H(2)O (3 center dot 5/2H(2)O), [(Fe2LEt)-L-II(NCS)(4)]center dot 1/2H(2)O (4 center dot 1/2H(2)O), [(Fe2LEt)-L-II(NCSe)(4)] (5), [(Fe2LEt)-L-II(NCBH3)(4)]center dot 3/2H(2)O (6 center dot 3/2H(2)O), [(Fe2LMix)-L-II(NCS)(4)]center dot 1/2H(2)O (7 center dot 1/2H(2)O), [(Fe2LMix)-L-II(NCSe)(4)]center dot 3/2H(2)O (8 center dot 3/2H(2)O), and [(Fe2LMix)-L-II(NCBH3)(4)]center dot 3/2H(2)O (9 center dot 3/2H(2)O). Complexes 3 center dot 5/2H(2)O, 4 center dot 1/2H(2)O, 5, 6 center dot 3/2H(2)O, and 8 center dot 3/2H(2)O were structurally characterized by X-ray crystallography, revealing, in all cases, both of the iron(II) centers in an octahedral environment with two NCE (E = S, Se, or BH3) anions in a cis-position relative to one another. Variable temperature magnetic susceptibility measurements showed that: all nine diiron(II) complexes are stabilized in the [HS-HS] state from 300 K to 4 K, and exhibit weak antiferromagnetic coupling. Mossbauer spectroscopy confirmed the spin and oxidation states of eight of the nine complexes (the synthesis of air-sensitive complex 3 was not readily reproduced).

• 出版日期2012-8-20