The first deprotonation of a borohydride anion was achieved by treatment of [BH(CN) ] with strong non-nucleophilic bases, which resulted in the formation of alkali-metal salts of the tricyanoborate dianion B(CN) in up to 97 % yield and 99.5 % purity. [BH(CN) ] is less acidic than (Me Si) NH but a stronger acid than iPr NH. Less sterically hindered, more nucleophilic bases such as PhLi and MeLi mostly attack a CN group under formation of imine dianions [RC(N)B(CN) ] , which can be hydrolyzed to ketones of the [RC(O)B(CN) ] type. The boron-centered nucleophile B(CN) reacts with CO and CN reagents to give salts of the [B(CN) CO ] dianion and the tetracyanoborate anion [B(CN) ] , respectively, in excellent yields.

A series of 12 lanthanide coordination polymers was synthesized from anhydrous LnCl 3 and 1,2-di(4-pyridyl)ethylene (dpe) under solvothermal conditions in either thiazole (thz) or pyridine (py). The reactions yielded ∞ 1 [Ln 2 Cl 6 (dpe) 2 (thz) 4 ]•dpe with Ln = Ce (1), Nd (2), ∞ 1 [LnCl 3 (dpe)(py) 2 ]•(dpe/py) with Ln = Gd (3), Er (4), and ∞ 1 [LnCl 3 (dpe) (thz) 2 ](dpe/thz) with Ln = Sm (5), Gd (6), Tb (7), Dy (8), Er (9), Yb (10), as well as ∞ 1 [HoCl 3 (dpe)(thz) 2 ]•thz (11) and ∞ 2 [La 2 Cl 6 (dpe) 3 (py) 2 ]•dpe ( 12). One-dimensional coordination polymers (CPs) and a two-dimensional network of five different constitutions are formed by connection of LnCl 3 units via dpe molecules. As free ligand, dpe shows an excimer effect that is reduced in the coordination polymers. In addition, dipyridylethylene proves to be a suitable sensitizer for the photoluminescence of lanthanides in the near-infrared region (NIR) only. Thereby, dpe differs from the related ligand 1,2-di(4-pyridyl)ethane. For the compounds presented, four different luminescence effects were detected: luminescence based on fluorescence of the linker dpe is observed in the visible region, whereas ligand-sensitized 4f−4f NIR emission is dominating for trivalent Nd, Er, and Yb. The Er-containing CPs show an inner-filter effect of Er 3+ , which is based on reabsorption of emission of dpe triggering the erbium NIR emission.

Die Reaktionen von [BH(CN) 3 ] À mit starken nichtnucleophilen Basen sind die ersten Beispiele fürd ie Deprotonierung eines Hydridoborat-Anions.D iese liefern Alkalimetall-Salzem it dem Tricyanoborat-Dianion B(CN) 3 2À in bis zu 97 %A usbeute und 99.5 %R einheit. [BH(CN) 3 ] À ist weniger acide als (Me 3 Si) 2 NH, aber eine stärkere Säure als iPr 2 NH. Sterischw eniger gehinderte,s t ärker nucleophile Basen wie PhLi und MeLi greifen hauptsächlichd ie CN-Gruppen unter Bildung von Imino-Dianionen [RC(N)B(CN) 3 ] 2À an, die mit Wasser zu Ketonen vom Typ[RC(O)B(CN) 3 ] À reagieren. Das Bor-zentrierte Nucleophil B(CN) 3 2À reagiert mit CO 2 und CN + -Reagenzien in exzellenten Ausbeuten zu Salzen mit dem [B(CN) 3 CO 2 ] 2À -b zw.d em Tetracyanoborat-Anion [B-(CN) 4 ] À .

Pentafluoroethyltricyanoborate frameworks of rare-earth metal ions of the general formula [Ln{CFB(CN)}(OH)] (Ln = La, Eu, Ho; n = 0, 3; [Ln1(OH)]) were synthesized using the oxonium salt (HO)[CFB(CN)] ((HO)1) and lanthanide chlorides LnCl·nHO as starting compounds. Single-crystals of [La{CFB(CN)}] ([La1]) are obtained from the room temperature ionic liquid (RTIL) [EMIm]1 using either a ionothermal approach or by recrystallization of anhydrous microcrystalline [La1] that is obtained from reactions in aqueous media after drying in a vacuum. Removal of water from [Ln1(OH)] (Ln = Eu, Ho) to give microcrystalline [Ln1] is achieved in a vacuum at elevated temperatures. All compounds were characterized by vibrational and NMR spectroscopy, thermogravimetry, and elemental analysis. The structures of the three-dimensional coordination polymers [Eu1(OH)] and [La1] were elucidated by single-crystal X-ray-diffraction. According to powder diffraction studies on anhydrous [Ln1] (Ln = La, Eu, Ho), the three compounds are isotypic. A study of the photoluminescence properties reveals that both Eu compounds, [Eu1] and [Eu1(OH)], are strongly luminescent, the emission of the anhydrous framework being significantly more intense than the one of the hydrate. The Eu-compounds benefit from a sensitizer effect of the anion. In contrast, the Ho-containing framework [Ho1] exhibits separate chromophores and a strong reabsorption of the fluorescence by the Ho ions.

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