Historic Prussian blue (PB) pigment is easily obtained as an insoluble precipitate in quantitative yield from an aqueous mixture of Fe 3+ and [Fe II (CN) 6 ] 4− (Fe 2+ and [Fe III (CN) 6 ] 3−). It has been found that the PB pigment is inherently an agglomerate of 10-20 nm nanoparticles, based on powder x-ray diffraction (XRD) line broadenings and transmission electron microscopy (TEM) images. The PB pigment has been revived as both organic-solvent-soluble and water-soluble nanoparticle inks. Through crystal surface modification with aliphatic amines, the nanoparticles are stably dispersed from the insoluble agglomerate into usual organic solvents to afford a transparent blue solution. Identical modification with [Fe(CN) 6 ] 4− yields water-soluble PB nanoparticles. A similar ink preparation is applicable to Ni-PBA and Co-PBA (nickel and cobalt hexacyanoferrates). The PB (blue), Ni-PBA (yellow), and Co-PBA (red) nanoparticles function as three primary colour inks.

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New way to benzylic amines! Fe‐catalyzed oxidative cross‐coupling of electron‐rich heteroarenes and methylamines is established. Under the influence of FeCl2/bipy catalyst and oxidant (pyridine N‐oxide or H2O2), thiophenes, furans, indoles, and azaindoles cross‐couple with methylamines to furnish the corresponding benzylic amines. An intramolecular CH/CH coupling of a thiophene is observed to afford a good ligand for the σ1 receptor protein.

The influence of association on the redox potential of vat dyes has been studied by means of a simple theoretical model. The calculation method used is illustrated by the information flow chart (Fig. l ) , which indicates also how the program in UNIVAC-111-FORTRAN-IV has been written. The results obtained are summarized in Fig. 2. (5. X I . 64) Theoretisch sollte die Fragmenticrung eincs y-Aminohalogenids (I) mit grosster Leichtigkeit nach dem einstufigen, synchronen Mechanismus a) erfolgen, wenn sowohl die Ca-X-Bindung als auch das Orbital des freien Elektronenpaares am Stickstoffatom (N-Elektronenpaar) anti und parallel, d. h. anti-periplanar, zur gelosten Cp-Cy-Bindung orientiert sind [l]. 1Wie kiirzlich mitgeteilt wurde [Z], gehen 1-Amino-3-brom-adamantane (2a), welche die obigen stereoelektronischen Bedingungen erfiillen, nach diesem Mechanismus in Carbimonium-Salze 3 iiber. Dabei ist die Geschwindigkeit dieser Fragmentierungs-Reaktion wesentlich grosser als diejenige der Solvolyse der homomorphen 1-Alkyl-3-brom-adamantane (2b), welche unter denselben Bedingungen eine unimolekulare Substitution (S,1-Reaktion) erleiden 121.Anderseits reagieren die acyclischen und daher konstellativ uneinheitlichen 3-Chlor-cr, a'-dimethyl-propylamine (4, R = H, CH,) etwas langsamer als die homomorphen Alkylchloride 5, R = H, CH,, was gegen eine direkte Beteiligung des Stickstoffatoms am Reaktionsgeschwindigkeits-bestimmenden Schritt spricht. Da zudem bei

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