The present invention relates to detectors for detecting fluorine-containing compounds and/or cyanide containing compounds, including hydrogen fluoride (HF) or HCN gas, hydrofluoric acid in solution, selected chemical warfare agents, selected industrial chemicals which may be hydrolyzed to release HF or HCN gas, compounds containing a cyanide group, and compounds that can release HF or HCN. The detectors comprise i) an organometallic component containing at least one bis-substituted boryl group of the formula —B(RB)(RB′) wherein each RB and each RB′ is independently selected from H, halogen, C1-6 alkyl, OR6, N(R6)(R7), SR6, C3-20 aryl or heteroaryl, and C3-20 cycloalkyl or heterocycloalkyl groups, each of which may be optionally substituted, ii) a Lewis base component, and iii) a solid matrix component. The invention also relates to novel organometallic compounds containing at least one bis-substituted boryl group and their use in detectors for fluorine containing compounds and/or cyanide containing compounds.