Crystal structure of (E)-undec-2-enoic acid

Abstract

In the mol­ecule of the title low-melting α,β-unsaturated carb­oxy­lic acid, C11H20O2, the least-squares mean line through the octyl chain forms an angle of 60.10 (13)° with the normal to plane of the acrylic acid fragment (r.m.s. deviation = 0.008 Å). In the crystal, centrosymmetrically related mol­ecules are linked by pairs of O—H⋯O hydrogen bonds into dimers, forming layers parallel to the (041) plane.

Synthesis and Molecular Structures of (E)-non-2-enoic Acid and (E)-dec-2-enoic Acid

“…2) [21]. In contrast to this findings, the analogous α,β-unsaturated carboxylic acids crystallize either in orthorhombic (C3: Ibam) [9][10][11][12], monoclinic (C4: C2/c) [13], or triclinic (C5, C6, C11, C12: P-1) [14][15][16][17] space groups. The high-pressure form of acrylic acid crystallizes in the monoclinic space group P21/c (No.…”

“…14) [12]. Bond lengths and angles in C9 and C10 resemble closely values found in other α,β-unsaturated carboxylic acids [9][10][11][12][13][14][15][16][17][18][19]. The crystal structures of C9 and C10 are characterized by carboxylic acid inversion dimers linked by pairs of O-H···O hydrogen bonds.…”

“…The crystal structures of acrylic acid (C3) [9][10][11][12], and crotonic acid (C4) [13] have been known for more than 40 years, while recently the crystal structures of four more members of α,β-unsaturated carboxylic acids, (E)-pent-2-enoic acid (C5) [14], (E)-hex-2-enoic acid (C6) [15], (E)-undec-2-enoic acid (C11) [16], and (E)-dodec-2-enoic acid (C12) [17], respectively, have been reported. In addition, two crystal structure determinations of co-crystals containing C6 are also known [18,19].…”

Synthesis and Molecular Structures of the Lowest Melting Odd- and Even-Numbered α,β-Unsaturated Carboxylic Acids—(E)-Hept-2-Enoic Acid and (E)-Oct-2-Enoic Acid

“…The melting point alternation for the series of trans-α,β-unsaturated carboxylic acids C3 to C16 based on melting points known from the literature and this work is depicted in Figure 1 [17][18][19][20][21][35][36][37][38][39][40]. It is clear that C7 has the lowest melting point within the series of odd-numbered carboxylic acids, whereas C8 exhibits the lowest melting point within the series of even-numbered carboxylic acids, respectively.…”

“…Crystal structure determinations of α,β-unsaturated carboxylic acids have been known from the literature in the cases of acrylic acid (C3) [12][13][14][15] and crotonic acid (C4) [16] for more than 40 years, but the crystal structures of other members of α,β-unsaturated carboxylic acids, namely, (E)-pent-2-enoic acid (C5) [17], (E)-hex-2-enoic acid (C6) [18], (E)-non-2-enoic acid (C9), (E)-dec-2-enoic acid (C10) [19], (E)-undec-2-enoic acid (C11) [20], and (E)-dodec-2-enoic acid (C12) [21], respectively, have just recently been reported. In addition, two crystal structure determinations of co-crystals containing C6 are also known [22,23].…”