ChemInform Abstract: PREPARATION AND BORON‐11 NMR AND VIBRATIONAL SPECTRA OF PURE ISOMERIC HALOHYDRODECABORATES XNB10H10‐N2‐; X = CHLORINE, BROMINE, OR IODINE; N = 1 OR 2

Abstract

Die durch Halogenierung von B,"Hf.

Convenient Synthesis of [closo-B10H9-1-I]2– and [closo-B10H8-1,10-I2]2– Anions

“…The aqueous layer was treated with a concentrated solution of [Bu 4 N] + Br – (1.13 g, 3.5 mmol), and the resulting solid was collected by filtration, washed with hexane, and dried. The resulting crude product was recrystallized (MeOH/H 2 O) to give 1.16 g (90% yield) of salt 1­[Bu 4 N] as colorless needles: mp 215–220 °C; 1 H NMR (500 MHz, CD 3 CN) δ −0.1 to 0.9 (br m, 8H), 0.97 (t, J = 7.4 Hz, 24H), 1.36 (sext, J = 7.3 Hz, 16H), 1.56–1.64 (m, 16H), 3.07–3.13 (m, 16H), 3.62 (br q, J = 143 Hz, 1H); 11 B NMR (160 MHz, CD 3 CN) δ −28.4 (d, J = 130 Hz, 4B), −24.8 (d, J = 131, 4B), −8.6 (s, 1B), 0.4 (d, J = 146 Hz, 1B) [lit …”

“…Recrystallized from MeOH/CH 2 Cl 2 (needles), 78–80% yield: mp 120–123 °C; 1 H NMR (500 MHz, CD 3 CN) δ 0.0–1.1 (br m, 8H), 0.98 (t, J = 7.3 Hz, 24H), 1.35 (sext, J = 7.4 Hz, 16H), 1.57–1.64 (m, 16H), 3.05–3.09 (m, 16H); 11 B NMR (160 MHz, CD 3 CN) δ −24.5 (d, J = 132 Hz, 8B), −5.6 (s, 2B) [lit …”

“…In the series A – D (Figure ), dianion [ closo -B 10 H 10 ] 2– ( D ) is the most reactive toward electrophiles . In contrast to anions A – C , iodination of the [ closo -B 10 H 10 ] 2– ( D ) dianion is very fast and kinetically indistinguishable for the introduction of the first three substituents. , This inability to control the degree of cage iodination combined with the stereochemistry of the anion leads to complex mixtures of products, which can be separated by tedious electrophoresis or ion exchange chromatography, and some, such as [ closo -B 10 H 9 -1-I] 2– ( 1 ) and [ closo -B 10 H 8 -1,10-I 2 ] 2– ( 2 ), have been characterized by NMR, IR, and XRD , methods. Detailed analysis demonstrated that the apical isomer [ closo -B 10 H 9 -1-I] 2– ( 1 ) is the minor product (30%) between the two possible monoiodo isomers, when reaction was run at ambient temperature, and the equatorial isomer [ closo -B 10 H 9 -2-I] 2– is the sole product when iodination was conducted at −75 °C in EtOH …”