Interstellar molecules: guides for new chemistry

Abstract

Interstellar space is among the most remarkable chemical laboratories in the universe. The existence of many unstable species with low-valent main group elements in the interstellar medium inspired us to investigate the feasibility of laboratory synthesis of such unstable molecules. Particularly the lighter Group 14 element carbon plays a very important role in space astrochemistry. Low-valent carbon as well as silicon were detected in the interstellar environment. This article describes our recent efforts in developing amazing chemistry of heavier low-valent Group 14 elements. This study unravels that the disproportionation pathway of the low-valent Group 14 elements can be arrested by using a sterically protected ligand, then one can artificially generate the situation observed in the interstellar surrounding where the chance of disproportionation is very low as the molecules are extremely dilute.

[{2,6‐(Me2NCH2)2C6H3}Sn(μ‐OH)W(CO)5]2: A Transition‐Metal‐Coordinated Organotin(II) Hydroxide

“…The reaction of the intramolecularly coordinated chlorido(organo)stannylene-pentacarbonyltungsten complex [{2,6-(Me 2 NCH 2 ) 2 C 6 H 3 }Sn(Cl)W(CO) 5 ] (1) [13] with K[sBu 3 BH] gave the corresponding organotin(II) hydride complex 2 (Scheme 1) as a pale yellow air-and moisturesensitive solid material that is very soluble in organic solvents such as benzene or THF. [14] and [{2,6-(MeOCH 2 ) 2 C 6 H 3 }Sn(H)W(CO) 5 ] (1118 Hz).…”

“…A 1 m thf solution (0.3 mL) of K[sBu 3 BH] (0.3 mmol) was added to a solution of compound 1 (0.22 g, 0.3 mmol) in thf (20 mL) at -78°C. The reaction mixture was stirred at this temperature for 3 h and then warmed to room temperature.…”

Oxidative Addition of Diorgano Disulfides to Distannyne [{2,6‐(Me2NCH2)2C6H3}Sn]2

“…Treatment of a toluene solution of 2 with a stoichiometric amount of bis(dimethylthiocarbamoyl) disulfide, bis(2-aminophenyl) disulfide or bis(2-pyridyl) disulfide did not provide new oxidation products, and the starting complex 2 was detected by 1 H NMR spectroscopy of the crude reaction mixtures. In contrast, the reaction of 3 and 4 with a stoichiometric amount of bis(2-aminophenyl) disulfide or bis(2-pyridyl) disulfide yielded the corresponding organotin(IV) thio derivatives {2,6-(Me 2 NCH 2 ) 2 C 6 H 3 }Sn(S-C 6 H 4 -2-NH 2 ) 3 (5) and {2,6-(Me 2 NCH 2 ) 2 C 6 H 3 }Sn(S-C 5 H 4 N) 3 (6). Compounds 5 and 6 were also obtained when compound 1 was treated with 3 equiv.…”

“…The reactivity and theoretical studies implied E=E multiple-bond character in REER, [32] associated with the interesting structural aspects and their unusual reactivity. The most striking example is the finding by Power who highlighted the reversible reactions of distannynes ArSnSnAr with ethylene and cyclooctatetraene under ambient conditions, [32] and the unusual reactivity of multiply bonded heavier main-group compounds towards small molecules such as H 2 , CO, CO 2 and NH 3 . [32,33] Further development in this direction is based on the employment of bulky anionic ligands, which allow kinetic stabilization of these reactive p-block centers by providing steric protection as well as electronic stabilization.…”

“…(Me 2 NCH 2 ) 2 C 6 H 3 }Sn(SC 5 H 4 N) 3 (6). In addition, oxidation of 3 and 4 with the radical TEMPO (2,2,6,6-tetramethylpiperidin-1-oxyl) provided organotin(IV) hydroxide [{2,6-(Me 2 NCH 2 ) 2 C 6 H 3 }Sn(SC 6 H 4 -2-NH)(μ-OH)] 2 (7) and organotin(IV) oxide [{2,6-(Me 2 NCH 2 ) 2 C 6 H 3 }Sn(SC 5 H 4 N)(μ-O)] 3 (8).…”