The commonly used triethylsilyl per-fluoro-tetraphenylborate salt, [Et(3)Si(+)][F(20)-BPh(4) (-)], has been misidentified. As prepared, the cation is a hydride-bridged silane adduct [R(3)Si-H-SiR(3) (+)]. Under favorable circumstances it can be an effective source of the triethylsilylium ion Et(3)Si(+) but in the absence of a stabilizing base the potent electrophilicity of Et(3)Si(+) decomposes the "inert" F(20)-BPh(4) (-) counterion.

Unlike the "parent" carborane anion CHB(11)H(11)(-), halogenated carborane anions such as CHB(11)H(5)Br(6)(-) can be readily C-functionalized in high yield and purity, enhancing their utility as weakly coordinating anions.

What is the strongest acid? Can a simple Brønsted acid be prepared that can protonate an alkane at room temperature? Can that acid be free of the complicating effects of added Lewis acids that are typical of common, difficult-to-handle superacid mixtures? The carborane superacid H(CHB11 F11 ) is that acid. It is an extremely moisture-sensitive solid, prepared by treatment of anhydrous HCl with [Et3 SiHSiEt3 ][CHB11 F11 ]. It adds H2 O to form [H3 O][CHB11 F11 ] and benzene to form the benzenium ion salt [C6 H7 ][CHB11 F11 ]. It reacts with butane to form a crystalline tBu(+) salt and with n-hexane to form an isolable hexyl carbocation salt. Carbocations, which are thus no longer transient intermediates, react with NaH either by hydride addition to re-form an alkane or by deprotonation to form an alkene and H2 . By protonating alkanes at room temperature, the reactivity of H(CHB11 F11 ) opens up new opportunities for the easier study of acid-catalyzed hydrocarbon reforming.

What is the strongest acid? Can a simple Brønsted acid be prepared that can protonate an alkane at room temperature? Can that acid be free of the complicating effects of added Lewis acids that are typical of common, difficult-to-handle superacid mixtures? The carborane superacid H(CHB11 F11 ) is that acid. It is an extremely moisture-sensitive solid, prepared by treatment of anhydrous HCl with [Et3 SiHSiEt3 ][CHB11 F11 ]. It adds H2 O to form [H3 O][CHB11 F11 ] and benzene to form the benzenium ion salt [C6 H7 ][CHB11 F11 ]. It reacts with butane to form a crystalline tBu(+) salt and with n-hexane to form an isolable hexyl carbocation salt. Carbocations, which are thus no longer transient intermediates, react with NaH either by hydride addition to re-form an alkane or by deprotonation to form an alkene and H2 . By protonating alkanes at room temperature, the reactivity of H(CHB11 F11 ) opens up new opportunities for the easier study of acid-catalyzed hydrocarbon reforming.

Thionitrous acid (HSNO), a potential key intermediate in biological signaling pathways, has been proposed to link NO and H2S biochemistries, but its existence and stability in vivo remain controversial. We establish that HSNO is spontaneously formed in high concentration when NO and H2S gases are mixed at room temperature in the presence of metallic surfaces. Our measurements reveal that HSNO is formed by the reaction H2S + N2O3 → HSNO + HNO2, where N2O3 is a product of NO disproportionation. These studies also suggest that further reaction of HSNO with H2S may form HNO and HSSH. The length of the S-N bond has been derived to high precision and is found to be unusually long: 1.84 Å, the longest S-N bond reported to date for an R-SNO compound. The present structural and, particularly, reactivity investigations of this elusive molecule provide a firm foundation to better understand its potential physiological chemistry and propensity to undergo S-N bond cleavage in vivo.