Synthese und strukturelle Charakterisierung von Borsubphthalocyaninaten

Synthesis and Structural Characterization of Boron Subphthalocyaninates Halosubphthalocyaninatoboron, [B(X)_spc] (X = F, Cl, Br) is obtained by heating phthalonitrile with boron trihalide in quinoline (X = F) or the corresponding halobenzene, resp. [B(C₆H₅)_spc] is prepared from phthalonitrile and tetraphenylborate or tetraphenyloboron oxide, resp. [B(OR)_spc] (R = H, CH(CH₃)₂, C(CH₃)₃, C₆H₅) is synthesized by bromide substitution of [B(Br)_spc] in pyridine/HOR. Substitution of [B(Br)_spc] in carboxylic acids yields [B(OOCR)_spc] (R = H, CX₃ (X = H, Cl, F), CH₂X (X = Cl, C₆H₅), C₆H₅). All subphthalocyaninates are characterized electrochemically and by UV‐VIS, IR/FIR, resonance Raman, and ¹H/¹⁰B‐NMR spectroscopy. Typical B–X stretching vibrations are at 622 (X = Br), 950 (Cl), 1063 (F), 1096 cm^–1 (OH) as well as between 1119 and 1052 cm^–1 (OR) resp. 985 and 1028 cm^–1 (OOCR). The difference ν(C=O)–ν(C–O) > 400 cm^–1 confirms the unidentate coordination of the carboxylato ligands. According to the crystal structure analysis of [B(OH)_spc], [B(OH)_spc] · 2 H₂O, [B(C₆H₅)_spc], [B(OC(CH₃)₃)_spc], [B(OOCCH₃)_spc] · 0.5 H₂O · C₂H₅OH and [B(OOCCH₃)_spc] · 0.4 H₂O · 1.1 C₅H₅N the _spc ligand is concavely distorted. This saucer shaped conformation is independent of the acido ligands and the presence of solvate. The outermost C atomes are vertically displaced in part by more than 2 Å from the N_i plane. The B atom is in a distorted tetrahedral coordination geometry. It is displaced by ca 0.64 Å out of the N_i plane towards the acido ligand. The average B–N distance is 1.500 Å, and the B–O distances range from 1.418(5) to 1.473(2) Å.