Temperature and H/D Isotopic Effects in the IR Spectra of the Hydrogen Bond in Solid-State 2-Furanacetic Acid and 2-Furanacrylic Acid

Figure 9

Polarized IR spectra of (a) d₁-2-furanacetic acid and (b) d₁-2-furanacrylic acid crystals measured at 77 K in the 𝜈_O-D band frequency range. (a) 2-Furanacetic acid crystal (ca. 10% H and 90% D). (I) The electric field vector 𝐸 parallel to the 𝑎-axis, (II) The 𝐸 vector parallel to the 𝑐*-axis. (b) 2-Furanacrylic acid crystal (ca 65% H and 35% D). (I) The electric field vector 𝐸 parallel to the c-axis, (II) The E vector parallel to the 𝑎*-axis.

(a)

(b)