We synthesized platinum(II) organometallic complexes with 3,8-bis-(triethylsilyl)ethynyl-1,10-phenanthroline (3,8-Phen-TES) and six respective arylethynyl ligands with different substituents (Pt(3,8-Phen-TES)(-Ph-R)2: R = H (1TES), 4-Me (2TES), 4-CF3 (3TES), 4-t-Bu (4TES), 3,5-di-CF3 (5TES), 3,5-di-t-Bu (6TES)), and characterized their luminescence in solution and solid state by photoluminescence spectroscopy. The luminescence of the 1TES – 6TES complexes in solution was assigned to the phosphorescence from the mixed transition of 3MLCT/3LLCT (LLCT = ligand-to-ligand charge transfer), revealing the similarity to emission spectra of previously reported platinum(II) organometallic complexes Pt(L)(-aryl)2 (L = several diimines) in solution. However, the color of the six complexes in the solid state ranged from orange to dark red compared to the yellow or light orange of the respective complexes in solution. The emission spectra of 5TES and 6TES in the dried powder sample were obviously observed at a long wavelength area over a wide range (520–1000 nm) relative to the spectra of their corresponding complexes in solution. The luminescence of 5TES in the solid state was assigned to the phosphorescence from the transition of a metal−metal-to-ligand charge transfer (3MMLCT), while the emission of 6TES in the solid state was assigned to the emission from the 3MLCT/3LLCT mixed transition. Vapochromism and vapoluminescence experiments with 13 species of volatile organic compounds (VOCs) for 6TES clearly showed that the multicolor change in the case of several VOCs could be seen with the naked eye, and that 6TES is superior to previous complexes reported by our group for VOC detection. The results suggest that the vapochromism and vapoluminescence of 6TES are induced by sterically hindered ligands with (3,5-di-t-butyl-phenyl)ethynyl and 3,8-Phen-TES, and that the expansion of the space between molecules in the solid state was important for multicolor detection of VOCs with vapochromism.