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The dye and pigment manufacturing industry is one of the most polluting in the world. Each year, over one million tons of petrochemical colorants are produced globally, the synthesis of which generates a large amount of waste. Naturally occurring, plant‐based dyes, on the other hand, are resource intensive to produce (land, water, energy), and are generally less effective as colorants. Between these two extremes would be synthetic dyes that are fully sourced from biomass‐derived intermediates. The present work describes the synthesis of such compounds, containing strong chromophores that lead to bright colors in the yellow to red region of the visible spectrum. The study was originally motivated by an early report of an unidentified halomethylfurfural derivative which resulted from hydrolysis in the presence of barium carbonate, now characterized as a butenolide of 5‐(hydroxymethyl)furfural (HMF). The method has been generalized for the synthesis of dyes from other biobased platform molecules, and a mechanism is proposed. [ABSTRACT FROM AUTHOR]

In Latvia, iron oxide pigments for paints, stains and coatings are all imported, although the land is rich in sources of iron (earth colour). The aim of this study was to evaluate earth colour deposits in Latvia and to assess the possibilities for their use in natural earth pigment manufacturing. The study included tests of colour pigments available in the Latvian market, as well as evaluation of samples from earth colour deposits in Lunkeči and Kazuleja in Latvia, to determine their quality, chemical composition, and physical characteristics. The research continued with tests of production technology for inorganic pigment manufacturing (enrichment, processing, etc.). The study results showed that the quality of the pigments obtained does not differ significantly from the supply available in the market, pointing to the potential use of natural iron oxide deposits in Latvia for inorganic pigment manufacturing. [ABSTRACT FROM AUTHOR]

New π-conjugated structures are constantly the subject of research in dyes and pigments industry and electronic organic field. In this context, the triphenodioxazine (TPDO) core has often been used as efficient photostable pigments and once integrated in air stable n-type organic field-effect transistor (OFET). However, little attention has been paid to the TPDO core as soluble materials for optoelectronic devices, possibly due to the harsh synthetic conditions and the insolubility of many compounds. To benefit from the photostability of TPDO in dye-sensitized solar cells (DSCs), an original synthetic pathway has been established to provide soluble and dissymmetric molecules applied to a suitable design for the sensitizers of DSC. The study has been pursued by the theoretical modeling of opto-electronic properties, the optical and electronic characterizations of dyes and elaboration of efficient devices. The discovery of new synthetic pathways opens the way to innovative designs of TPDO for materials used in organic electronics. [ABSTRACT FROM AUTHOR]