This article reviews the spectroscopic properties of hydrogen bound to a la
rge variety of synthetic compounds like simple oxides, perovskites, the LiN
bO3 family, KTP, sillenites, eulytites, berates, garnets, spinels and some
others. In almost all compounds the OH stretch mode is found in the range 3
200-3700 cm(-1), with isotope replica of deuterium (2350-2750 cm(-1)) and a
few examples of tritium (2050-2250 cm(-1)). The fundamental vibration, the
isotope replica and the corresponding overtones are described with an anha
rmonic oscillator model. A nonlinear relation between the anharmonicity and
the harmonic frequency is found and interpreted using recent second order
perturbation calculations. An often pronounced temperature dependence of th
e stretch mode and phonon coupling is discussed. Data for the stretching vi
bration influenced by additional weak or strong doping are presented. Atomi
stic defect models are described and tested by means of light polarization,
external perturbations like pressure and electric field, and Raman scatter
ing analyzed with the behavior-type method. The last section briefly review
s applications profiting from doping with hydrogen and its easy detection b
y means of the OH stretch mode.