Elucidation of the Fe(III) Gallate Structure in Historical Iron Gall Ink.

Synthetic, structural, spectroscopic and aging studies conclusively show that the main colorant of historical iron gall ink (IGI) is an amorphous form of Fe(III) gallate·xH2O (x = ∼1.5-3.2).

Composition and particle size of superparamagnetic corrosion products in tap water.

Chemical analyses, magnetization, Mössbauer spectrum, and x-ray diffraction measurements were made on solids removed from tap water by means of membrane filters. The taps from which this water was obtained had previously been unused for prolonged periods of time. When these taps were reactivated and water was first drawn, it was observed that the quantity of coarse solids in the water gradually decreased with flow, while at the same time the quantity of fine solids gradually increased.

A DFT computational study of spin crossover in iron(III) and iron(II) tripodal imidazole complexes. A comparison of experiment with calculations.

B3LYP* functionals were used to model the sixteen iron(II) (1A, LS and 5T, HS) and iron(III) (2T, LS and 6A, HS) complexes of the 1 : 3 Schiff base condensate of tris(2-aminoethyl)amine and imidazole-4-carboxaldehyde, H3L1, and its deprotonated forms, [H2L1]1-, [HL1]2-, and [L1]3-. This ligand system is unusual in that [FeH3L1]3+, [FeH3L1]2+ and [FeL1]- all exhibit a spin crossover between 100-300 K. This makes these complexes ideal for a hybrid DFT computational approach and provides an opportunity to refine the value of the exact exchange admixture parameter, c3, and to predict properties of partially protonated complexes that are not experimentally available.

A DFT computational study of spin crossover in iron(III) and iron(II) tripodal imidazole complexes. A comparison of experiment with calculations.

B3LYP* functionals were used to model the sixteen iron(II) (1A, LS and 5T, HS) and iron(III) (2T, LS and 6A, HS) complexes of the 1:3 Schiff base condensate of tris(2-aminoethyl)amine and imidazole-4-carboxaldehyde, H3L1, and its deprotonated forms, [H2L1]1-, [HL1]2-, and [L1]3-. This ligand system is unusual in that [FeH3L1]3+, [FeH3L1]2+ and [FeL1]- all exhibit a spin crossover between 100-300 K. This makes these complexes ideal for a hybrid DFT computational approach and provides an opportunity to refine the value of the exact exchange admixture parameter, c3, and to predict properties of partially protonated complexes that are not experimentally available.

Synthesis and characterization of a spin crossover iron(II)-iron(III) mixed valence supramolecular pseudo-dimer exhibiting chiral recognition, hydrogen bonding, and pi-pi interactions.

Reaction of iron(II) and the 3 : 1 Schiff base condensate of 5-methylpyrazole-3-carboxaldehyde and tris(2-aminoethyl)amine in air gives a pseudo-dimer complex with a triple helix structure made of Delta-Delta and Lambda-Lambda pairings of spin crossover iron(II) and low spin iron(III) cations that are held together by three pi-pi and hydrogen bonding interactions.

Synthesis and characterization of manganese(II) and iron(III) d5 tripodal imidazole complexes. Effect of oxidation state, protonation state and ligand conformation on coordination number and spin state.

The 1 : 3 Schiff base condensates of tris(2-aminoethyl)amine (tren) or tris(3-aminopropyl)amine (trpn) with 4-methyl-5-imidazolecarboxaldehyde, H3L1 and H3L2, respectively, were generated in situ and used to prepare complexes with manganese(II) and iron(III). The resultant complexes, [MnH3L1](ClO4)2, [MnH3L1](ClO4)2.EtOH.

Synthesis and characterization of seven-coordinate tripodal imidazole complexes of iron(II) and manganese(II).

The iron(II) and manganese(II) complexes of the N(7) Schiff-base condensate of tris(3-aminopropyl)amine with 1-methyl-2-imidazolecarbaldehyde and the manganese(II) complex of the N(7) Schiff-base condensate of tris(3-aminopropyl)amine with 4-imidazolecarbaldehyde are high-spin mono capped octahedral seven-coordinate complexes with a short, approximately 2.44 è, metal to apical nitrogen bond.

Proton control of oxidation and spin state in a series of iron tripodal imidazole complexes.

Reaction of iron salts with three tripodal imidazole ligands, H(3)(1), H(3)(2), H(3)(3), formed from the condensation of tris(2-aminoethyl)amine (tren) with 3 equiv of an imidazole carboxaldehyde yielded eight new cationic iron(III) and iron(II), [FeH(3)L](3+or2+), and neutral iron(III), FeL, complexes. All complexes were characterized by EA(CHN), IR, UV, Mössbauer, mass spectral techniques and cyclic voltammetry. Structures of three of the complexes, Fe(2).