Synthesis and Characterization of Cyclotriphosphazenes Bearing Chalcones Derivatives

A series of new cyclotriphosphazenes bearing chalcones derivatives, N₃P₃Cl₅[OC₆H₄ CH=CHC(O)C₆H₄OC_nH_2n+1] and N₃P₃[OC₆H₄CH=CHC(O)—C₆H₄OC_nH_2n+1]₆, has been synthesized. A convenient synthetic method was performed from the reaction of hexachlorocyclotriphosphazenes with one and six equivalents of (E)-3-(4-(alkyloxy)phenyl)-1-(4-hydroxyphenyl)prop-2-en-1-one (2a–c). The compounds differ in the length of alkyl groups, C_nH_2n+1, where n = 10, 12, and 14, respectively. All the products were obtained in high yields. The structures of the synthesized compounds were defined by elemental analysis, IR, ¹H, ¹³C, and ³¹P NMR.     

Alkyloxy- and aryloxy-titanocenes: Synthesis, solid-state structure and cyclic voltammetric studies

Alkyloxy- and aryloxy-functionalized titanocenes of type [Ti](Cl)(OR) (R = Me (2), CH₂PPh₂ (3), CH₂Fc (4), C₆H₅ (5), C₆H₄-4-CN (6), C₆H₄-4-NO₂ (7), C₆H₄-4-Me (8), C₆H₄-4-OMe (9), C₆H₄-4-C(O)Me (10), C₆H₄-4-CO₂Me (11), C₆H₄-3-NO₂ (12); [Ti] = (η⁵-C₅H₄SiMe₃)₂Ti; Fc = (η⁵-C₅H₄)(η⁵-C₅H₅)Fe) were synthesized by the reaction of [Ti]Cl₂ (1) with ROH in a 1:1 molar ratio and in presence of Et₂NH. Diaryloxy-titanocenes (e.g., [Ti](OC₆H₄-4-NO₂)₂ (13)) are accessible, when the ratio of 1 and ROH is changed to 1:2. This synthesis methodology also allowed the preparation of dinuclear complexes of composition ([Ti](Cl))₂(μ-OC₆H₄O) (14) and ([Ti](Cl)(μ-OC₆H₄-4))₂ (15) by the reaction of 1 with hydroquinone or 1,1′-dihydroxybiphenyl in a 2:1 stoichiometry.Cyclic voltammetric studies show the characteristic [Ti(IV)/Ti(III)] reductions. It was found that the potentials of the alkyloxy titanocenes 2–4 do not differ, while for the aryloxy-titanocenes 5–15 the reduction potentials correlate linearly with the σ_p/m Hammett substituent constants showing a strong influence of the substituents on the electron density at titanium.The structures of titanocenes 4, 5, 9, and 11–13 in the solid state are reported. Typical for these organometallic sandwich compounds is a distorted tetrahedral coordination geometry around titanium with D1–Ti–D2 angles (D1, D2 = centroids of the cyclopentadienyl ligands) of ca. 130 °. In comparison to FcCH₂O-functionalized 4, for the aryloxy-titanocenes 5, 9, and 11–13 a significant larger Ti–O–C angle was found confirming electronic interactions between the titanium atom and the appropriate aryl group.