Exploiting Raman spectroscopy and computational modeling, for the first time, we report and explain an interesting phenomenon in clay modified by cetyltrimethylammonium bromide. A splitting of the CH2-chain's symmetric C-C stretching Raman mode found at similar to 1128 cm(-1) in cetyltrimethylammonium bromide into two bands at 1128 and 1139 cm(-1) in clay modified by cetyltrimethylammonium bromide is observed. We demonstrate that this splitting appears if two types of trans-segments with nonequivalent lengths and terminal groups coexist in the CH2-chain of the alkylammonium ion embedded into the clay interlayer space. We report Raman experimental evidence for a CH2-chain bending within the clay galleries, resulting in the symmetric C-C stretching band splitting, as was also suggested by computational modeling. Noteworthy, we postulate that this unique behavior based on CH2-chain bending provides a general understanding of conformation reorganization and switching within long CH2-chain molecules confined within modified clay interlayer galleries. For all modifier concentrations, we show that the intercalated cetyltrimethylammonium ions exist in a liquid-like state, consisting mainly of trans conformations (similar to 86%) of two types in approximately equal proportions. Moreover, we demonstrate that the integral Raman intensity ratio I-1295(CH2)/I-705(clay) provides a rapid nondestructive quantification of the relative content of alkylammonium ions in modified clays. These results demonstrate that a simple direct monitoring of specific modifier-dependent interlayer conformational states is possible, which is of great importance for a tunable fabrication of modified clays-based nanocomposites with desired properties.