Organometallic−Organic Hybrid Crystals from Ferrocenyl Dipyridine and Binaphthol:  Different Crystal Structures and Nonlinear Optical Properties Depending upon the Reaction Medium and Optical Purity of Binaphthol

Abstract

The hydrogen bond directed molecular recognition between 1,1‘-bis(ethenyl-4-pyridyl)ferrocene (1) and (±)-1,1‘-binaphthol (2)/(−)-1,1‘- binaphthol ((−)-2) has been studied by cocrystallization in different solvents. Single-crystal X-ray structures reveal that 3:2, 2:1, and 1:1 complexes (3, 4, and 5, respectively) of 1,1‘-bis(ethenyl-4-pyridyl)ferrocene (1) and (±)-1,1-binaphthol (2) are formed in tetrahydrofuran, methanol, and ethanol, respectively. 5 has a noncentrosymmetric packing arrangement, and an efficiency of 0.3 times that of urea in second-harmonic generation has been measured at 1295 nm. An X-ray crystal structure of 6, 1:1 complex of 1 with (−)-2 in ethanol, reveals that all the molecular dipoles are aligned in the same direction (i.e, a polar crystal), but 6 has modest nonlinear optical properties (ca. 0.4 times that of urea).

Syntheses, Structures and Nonlinear Optical Properties of Ferrocenyl Complexes with Arylethenyl Substituents

“…Similar 1,1Ј-bis-substituted ferrocenyl complexes with pendant pyridine groups have been reported by Lee et al, and show very interesting structural features. [7] Scheme 1…”

Stilbene analogues incorporating the Co(η4-C4Ph4)(η5-C5H4-) end group

“…[43]. dipyridinyl [Fe(h 5 -C 5 H 4 CH]CH-C 5 H 5 N-E)2 ], but in supramolecular aggregates with binaphthol it can adopt other conformations[42].…”

Crystal Engineering with Structurally Flexible 1,1′‐Substituted Ferrocenes for Nonlinear Optical Materials

“…[12] However, in cocrystals of 2, 3, and 4, the two substituents on the cyclopentadienyl groups of the ferrocene are situated at 1-and 1Ј-positions, and 1 shows a syn-type geometry. Resorcinol and phloroglucinol molecules act like molecular clips to create simultaneous double hydrogen bonds with a molecule of 1 and fix its conformation as a dipolar one Ϫ a prerequisite for a nonlinear optical molecule.…”

“…The resultant solution turned dark green during stirring at room temperature for 1 h, after Table 2. Selected intra-and intermolecular bond lengths (Å ) and angles (°) for 1, [12] 2, 3, 4, and 5 1 C(1)ϪC (11) 1.46 (2) C (11)ϪC (12) 1.27 (2) C (12)ϪC (13) 1.49(2) C(6)ϪC (18) 1.495 (14) C (18) (7) 2.021 (5) Fe (1)ϪC (1) 2.053 (4) Fe (1)ϪC (6) 2.056(5) C(1)ϪC (11) 1.455 (6) C (11)ϪC (12) 1.307 (7) C (12)ϪC (13) 1.458 (7) C (6)ϪC (18) 1.463 (7) C (18)ϪC (19) 1.307 (7) C (19)ϪC (20) 1.460 (7) C (16)ϪN (1) 1.321 (8) C (22)ϪN (2) 1.344 (6) C (01)ϪO (01) 1.346(6) C(03)ϪO (02) 1.354 (7) N (1)ϪO (01) 2.733 (6) N (2)ϪO (02) 2.738(6) C (1)ϪFe (1)ϪC (6) 108.8 (2) O …”

“…[11] During an investigation into the preparation of chromophores with high NLO responses, we reported the crystal structures of 1,1Ј-bis(ethenyl-4-pyridyl)-ferrocene, 1, and its cocrystals with 1,1Ј-binaphthol. [12] The two substituents on the cyclopentadienyl group of 1 adopt a typical 1,3Ј-orientation, i.e., in anti-fashion. Cocrystals of 1 with 1,1Ј-binaphthol in methanol and ethanol have the two substituents of the ferrocene at the 1-and 1Ј-positions, respectively.…”