Synthesis and Structural Characterization of (µ-Oxido)Diiron(III)Tris(2-Pyridylmethyl)Amine Complexes

Oxido-bridged [Fe2(TPA)2OL]3+ complexes were synthesized using the tetradentate ligand TPA (tris(2-pyridylmethyl)amine) (L is defined below) and [{Fe(TPA)Br}2O]2+. All structural data were collected at 25 ℃. All but one are monoclinic. The anions are perchlorates. L = OAc•H2O polymorph 1: P21/c with a = 10.532(7) Å, b = 22.572(15) Å, c = 20.758(15) Å, β = 104.711(7)°, V = 4772.8(6) Å3. The structure was determined from 13844 out of a total 39507 reflections with R = 7.76%. L = OAc•H2O polymorph 2: P21/n with a = 10.601(4) Å, b = 22.529(8) Å, c = 20.923(8) Å, β = 104.192(4)°, V = 4844.3(3) Å3. The structure was determined from 9008 out of a total 24212 reflections with R = 7.25%. L = 4-hydroxybenzoate: P21/c with a = 14.451(6) Å, b = 16.760(7) Å, c = 20.594(7) Å, β = 101.824(4)°, V = 4882.1(3) Å3. The structure was determined from 8582 out of a total 18536 reflections with R = 5.06%. L = 4-methoxybenzoate: P21/c with a = 14.347(9) Å, b = 17.163(13) Å, c = 20.328(11) Å, β = 100.781(6)°, V = 4917.0(6) Å3. The structure was determined from 10168 out of a total of 19784 reflections with R = 6.08%. L = 4-fluorobenzoate: P21/c with a = 14.399(9) Å, b = 17.186(11) Å, c = 20.108(10) Å, β = 101.877(5)°, V = 4869.1(5) Å3. The structure was determined from 10056 out of a total of 21571 reflections with R = 4.50%.

L = 3,5-dihydroxybenzoate•CH3CN: P21/n with a = 13.1877(11) Å, b = 22.2892(12) Å, c = 19.7183(13) Å, β = 95.193(7)°, V = 5772.3(7) Å3. The structure was determined from 9021 out of a total of 18889 reflections with R = 8.34%. L = 3,5-dimethylbenzoate•0.5H2O: P-1 with a = 13.362(6) Å, b = 19.053(8) Å, c = 22.057(9) Å and α = 89.650(3)°, β = 74.093(4)°, γ = 84.094(3)°, V = 5370.3(4) Å3. The structure was determined from 19142 out of a total of 30995 reflections with R = 5.30%. {Fe(TPA)Br}2O2•H2O : C2/c with a = 16.148(17) Å, b = 17.204(13) Å, c = 16.852(12) Å, β = 111.204(10)°, V = 4364.6(7) Å3. The structure was determined from 3753 out of a total of 6891 reflections with R = 6.93%.