The invention provides luminescent solid-state compositions comprising difluoroboron beta-diketonates wherein the compositions can exhibit mechanochromic luminescence. The mechanochromic effect on the luminescence can be reversible, such as thermally reversible. Various solid-state forms of the invention can have emission spectra that differ from the properties of the respective difluoroboron beta-diketonate in solution. The mechanochromic effect can be stimulated by pressure such as handwriting, and can be reversed over a period of minutes to hours at room temperature. The invention also provides methods of making and methods of using the solid-state compositions, such as for sensors and for information displays for use in biological sensing, and in art, design, and consumer products. Compositions of the invention, such as compositions in nanoparticulate form, or contained within a matrix material, can be used in conjunction with fluorescence microscopy to provide information concerning pressures and tensions within and external to living cells, tissues, or organisms.