22364-91-6Relevant academic research and scientific papers
Contributions to the Chemistry of Boron. Part 160. A Convenient Synthesis of Catecholatoborane and Diborane
Maennig, Detlef,Noeth, Heinrich
, p. 1689 - 1692 (1985)
Catecholatoborane is formed in high yield (> 75percent) by ball milling NaBH4 and 2,2'-o-phenylenedioxybis(1,3,2-benzodioxaborole) in diethyl ether in the presence of small amounts of LiCl.It also results quantitatively from the first two components in di
Sodium Hydro(isothiocyanato)borates: Synthesis and Structures
Noeth, Heinrich,Warchhold, Marcus
, p. 1115 - 1124 (2007/10/03)
Sodium thiocyanate reacts in THF solution with 18-crown-6 to give the molecular compound Na(18-crown-6)(THF)NCS (3) with the N atom of the NCS anion oriented towards Na1+. The same reaction with 15-crown-5 yields the ion pair Na(15-crown-5)NCS (4). In contrast, Na(NCS)(py)4, obtained by treating a solution of Na(H3BNCS) in THF with pyridine, yields Na(py)4(NCS) (5), which has a chain structure with hexacoordinate Na atoms coordinated to five N atoms and an S atom. Na(NCS) in THF adds 1 equiv. of BH3 to give Na(H3BNCS)*nTHF. Addition of 18-crown-6 to this solution yields crystals of the salt [Na(18-crown-6)(THF)2][H3BNCS] (1), as shown by X-ray crystallography. Both the cation and the anion show site disorder. However, when 15-crown-5 is used for complexation, the salt [Na(15-crown-5)(THF)][H3BNCS] (2) can be isolated. Its anion shows an almost linear B-N-C-S unit. Only a mixture of (catecholato)(isothiocyanato)borates results on treating Na(NCS) in THF with catecholborane. However, the borate Na[catB(NCS)2] is readily formed by adding Na(NCS) to B-(isothiocyanato)catecholborane. Single crystals of this compound were obtained as the salt [Na(18-crown-6)(THF)2][catB(NCS)2] (6). On the other hand, the reaction of Na(NCS) with 9-borabicyclo[3.3.1]nonane (9-BBN) in THF yields Na[(9-BBN)NCS]*nTHF, and, on addition of 18-crown-6, the complex [Na(18-crown-6)(THF)2][(9-BBN)NCS] was isolated. Suitable crystal for X-ray structure determination were, however, only obtained by crystallization from tetrahydropyran. This solvate has the rather unusual structure [Na(18-crown-6)(thp)2][{(9-BBN)NC}2Na(thp)4] (8). The sodiate anion has an Na atom coordinated by two S and four O atoms. DFT calculations support these experimental results: The (isothiocyanato)borates are more stable than the thiocyanato isomers. For the latter a bent structure of the B-S-C-N unit with a B-S-C bond angle of 105.7 deg is predicted.
