Decachloro-closo-decaborate anion in copper(II) complexation reactions with N-donor ligands: 35Cl NQR and X-ray studies

Polyhalogenated Decaborate and 1‐Ammoniododecaborate Ions: An Improved Synthesis with Elemental Halogens, and Physicochemical and Chemical Properties

“…Similar arrangements of species incorporating two alkali‐metal cations, which are bridged, however, by two oxygen‐donor ligands, are known from the reported structures of the perhalogenated dodecaborate salts [Li 2 (SO 2 ) 8 ][B 12 Cl 12 ],[17l] [K 2 (H 2 O) n ][B 12 F 12 ] ( n = 2, 4) and [Na 2 (H 2 O) n ][B 12 X 12 ] (X = H, F, n = 4; X = Cl, n = 6). [17m] (4) The ammonio fragment is involved in the formation of three hydrogen bonds (N ··· N distances approx. 2.96 Å) to three non‐coordinated acetonitrile solvating molecules.…”

“…From previously published electrochemical studies on platinum electrodes in non‐aqueous solutions (CH 3 CN, CH 2 Cl 2 )[17e], it is known that [B 10 H 10 ] 2– can undergo two‐electron oxidation resulting in dimerization to the [B 20 H 18 ] 2– ion. In contrast, the electrochemistry of (Me 4 N) 2 [B 10 X 10 ] (X = Cl, Br) in organic solvents suggests the formation of the anion radical [B 10 X 10 ] · – with an unpaired electron.…”

“…(1) Only five crystal structures containing the ammonium group directly bound to the closo ‐dodecaborate dianion[18b], [19c] have previously been reported, but none of them contain iodine atoms. (2) There are seven structures of iodinated closo ‐dodecaborate dianions, of which three are periodo‐substituted[17d], and the remaining four correspond to species comprising only one iodine atom . No structure could be found that combines both substituents.…”

“…Surprisingly, there is only one example of a sodium cation surrounded by six acetonitrile molecules in the literature; all are arranged in terminal positions, thus forming a mononuclear species . Similar arrangements of species incorporating two alkali‐metal cations, which are bridged, however, by two oxygen‐donor ligands, are known from the reported structures of the perhalogenated dodecaborate salts [Li 2 (SO 2 ) 8 ][B 12 Cl 12 ],[17l] [K 2 (H 2 O) n ][B 12 F 12 ] ( n = 2, 4) and [Na 2 (H 2 O) n ][B 12 X 12 ] (X = H, F, n = 4; X = Cl, n = 6). [17m] (4) The ammonio fragment is involved in the formation of three hydrogen bonds (N ··· N distances approx.…”

“…This research was started by developing and updating the methods for perhalogenation[2b], and permethylation of the parent [B 12 H 12 ] 2– ion, which has been accompanied by numerous physicochemical and structural studies, focussing on the weakly coordinating properties of these species and the interactions with their cationic counterparts. [2b], [8b], , With the aim of decreasing the divalent charge of these anions, the –NH 3 group was introduced to obtain the corresponding fluorinated [1‐NH 3 B 12 F 11 ] –[15d,15e] and chlorinated [1‐NH 3 B 12 Cl 11 ] – derivatives from the previously reported univalent [1‐NH 3 B 12 H 11 ] – ion . To achieve undecachlorination of the latter ion, two reaction routes have been reported using either SbCl 5 or SO 2 Cl 2 reagents in CH 3 CN.…”