The chelat complexes of borontrifluoride and methyl- or methylene substituted 1,3-dicarbonylic compounds (2,2-difluor-1,3,2-(2H)-dioxaborines) are strong pi-elektron-acceptors. Their chemical and physical properties (absorption, fluorescence, crystalline structure or stability of hydrolysis) strongly depending of the substitution pattern we investigated. Other than the parent 1,3-dicarbonylic compounds the 2,2-difluor-1,3,2-(2H)-dioxaborines reacting with electrphilic reagents at the methyl- or methylengroup under forming of long conjugated pi-elektronsystems. By reaction of 2,2-difluor-1,3,2-(2H)-dioxaborines with various donator substituted formylderivatives a great number of donator-acceptor-systems, to attribute as merocyaninic deyes, were isolated and investigated to their spectroscopic properties. By reaction of 2,2-difluor-1,3,2-(2H)-dioxaborines with bifunctional electrophiles, anionic methine deyes of the oxonol type were formed. Some tri-, penta- and heptamethine deyes were isolated. To yield better crystallisze compounds a strategie to form neutral or cationic systems was developed. The heptamethine deyes showes a longwavelenght absorption and fluorescence in the near infrared region at about 900- 1080 nm, so these compounds are candidates for laser applications. The influence of some structural parameters (length of the methine chain, bridging groups in various positions and substitution pattern) to the chemical and physical properties of the oxonol deyes were discussed by spectral dataes and quantenchemical calculations..