In the crystal structure of the title molecular salt, C(13)H(30)N(5)O(+)·C(24)H(20)B(-), discrete guanidinium cations and tetra-phenyl-borate anions are present. The C-N bond lengths in the CN(3) unit are 1.3427 (12), 1.3445 (12) and 1.3453 (13) Å, indicating double-bond character. The central C atom is surrounded in a nearly ideal trigonal-planar geometry by three N atoms and the positive char...

In the title molecular salt, C(14)H(22)N(3) (+)·Br(-), the ring incorporating the guanidinium grouping exhibits a half-chair conformation and the dihedral angle between the N-C-N and C-C-C planes is 55.0 (3)°. The C-N bond lengths in the central CN(3) unit are 1.333 (4), 1.338 (3) and 1.341 (4) Å, indicating partial double-bond character. The central C atom is bonded to the three N atoms in a n...

In the crystal structure of the title salt, C(12)H(30)N(4) (2+)·2C(24)H(20)B(-), the C-N bond lengths in the central CN(3) unit of the guanidinium ion are 1.3388 (17), 1.3390 (16) and 1.3540 (17) Å, indicating partial double-bond character in each. The central C atom is bonded to the three N atoms in a nearly ideal trigonal-planar geometry and the positive charge is delocalized in the CN(3) pla...

The analogy between ZnR fragments and the hydrogen radical represents a fruitful concept in organometallic synthesis. The organozinc(II) and -zinc(I) sources ZnMe2 (Me 1⁄4 methyl) and [Zn2Cp*2] (Cp* 1⁄4 pentamethylcyclopentadienyl) provide one-electron fragments $ZnR (R 1⁄4 Me, Cp*), which can be trapped by transition metal complexes [LaM], yielding [Lb(ZnR)n]. The addition of the dizinc compou...

By chain extension of polysarcosine with phenylalanine and cystine, nanogels are formed. The facilitate the transport dyes across an artificial mucus coated membrane their release by reductive bond cleavage.

Human acid beta-glucosidase (D-glucosyl-N-acylsphingosine glucohydrolase, EC 3.2.1.45) cleaves the beta-glucosidic bonds of glucosylceramide and synthetic beta-glucosides. The specificity of binding to the active site of this enzyme was evaluated using series of inhibitors including synthetic sphingosines, N-alkyl(Cn)-deoxynojirimycins (1,5-dideoxy-5-iminoglucose) and N-Cn-glucosylamines. The s...

The title compound, C(12)H(28)N(6), is located about an inversion center situated at the center of the -CH(2)-CH(2)- bond. The C-N bond lengths are 1.285 (2), 1.384 (2) and 1.395 (1) Å, indicating double- and single-bond character. The N-C-N angles are 114.1 (1), 119.3 (1) and 126.5 (1)°, showing a deviation of both CN(3) planes from an ideal trigonal-planar geometry.

A novel selectively sequential C-S/C-N bond activation is presented. Through the combination of an Ugi-4CR and cleavage, diverse peptidomimetics containing a primary amide are prepared in a...

Deoxygenative coupling of CO to value-added C≥2 products is challenging and mechanistically poorly understood. Herein, we report a mechanistic investigation into the reductive coupling of CO, which provides new fundamental insights into a multielectron bond-breaking and bond-making transformation. In our studies, the formation of a bis(siloxycarbyne) complex precedes C-O bond cleavage. At -78 °...

Bacteria resistant to methylmercury utilize two enzymes (MerA and MerB) to degrade methylmercury to the less toxic elemental mercury. The crucial step is the cleavage of the carbon-mercury bond of methylmercury by the organomercurial lyase (MerB). In this study, we determined high resolution crystal structures of MerB in both the free (1.76-A resolution) and mercury-bound (1.64-A resolution) st...