1-(Methoxymethyl)pyrene

The title compound, C18H14O, crystallizes with aromatic �–� stacking interactions

Crystal structure of 25,26,27,28-tetrabenzyloxy-5,11,17,23-tert-butylcalix- [4]arene, C72H80O4

C72H80P4, monoclinic, P121/n1 (no. 14), a = 10.3709(3) Å, b = 23.2467(6) Å, c = 25.1444(7) Å, β= 92.660(1)°, V = 6055.5 Å3, Z = 4, R gt(F) = 0.060, wRref(F2) = 0.190, T = 273 K

Trimethyl 3,3',3''-(benzene-1,3,5-triyl)tripropynoate

In the crystal of trimethyl 3,3',3''-(benzene-triyl)tripropynoate, a system of new hydrogen bond ring motifs involving C-H...O interactions give rise to layer formation of molecules while the layers are connected among each other via weak contacts of C---H...O and C---H...pi type to specifically complete the supramolecular packing structure

Different supramolecular interactions mediated by bromine atoms in the crystal structures of three anisole derivatives

Three anisole building blocks featuring bishydroxymethyl or bisbromomethyl pendants have been analyzed with regard to their molecular structure and packing behaviour. A typical supramolecular pattern we found were C—H···π interactions responsible for the generation of molecular stacks. π···π Interactions were only observed in the absence of bromine indicating a striking influence on the distances between adjacent aromatic moieties. When comparing the bishydroxymethyl compound with the respective bisbromomethyl compound we found that the strong O—H···O in the zigzag arrangement in the first is replaced by C—H···Br interactions in the second without changing the general packing

Benchmarking Image Sensors Under Adverse Weather Conditions for Autonomous Driving

Adverse weather conditions are very challenging for autonomous driving because most of the state-of-the-art sensors stop working reliably under these conditions. In order to develop robust sensors and algorithms, tests with current sensors in defined weather conditions are crucial for determining the impact of bad weather for each sensor. This work describes a testing and evaluation methodology that helps to benchmark novel sensor technologies and compare them to state-of-the-art sensors. As an example, gated imaging is compared to standard imaging under foggy conditions. It is shown that gated imaging outperforms state-of-the-art standard passive imaging due to time-synchronized active illumination

1-(Hydroxymethyl)pyrene

The asymmetric unit of the title compound, C17H12O, contains two molecules, in which the fused aromatic ring systems are almost planar [maximum deviations = 0.0529 (9) and 0.0256 (9) Å]. In the crystal, aromatic π–π stacking interactions (perpendicular distance of centroids of about 3.4 Å) and strong O—H...O hydrogen bonds result in a helical arrangement of pyrenyl dimers

Does the exception prove the rule? - A comparative study of supramolecular synthons in a series of lactam esters

In this paper a series of simple lactam esters and carboxylic acids is studied with respect to their overall conformation and hydrogen bonding patterns. In total, eight lactams featuring Nα-substitution have been synthesized. Additionally, the molecular structures of related lactam esters have been considered. The length of the amide bonds does not seem to be majorly influenced by different substituents unless the electron withdrawing N-Boc-protection group is introduced, resulting in a higher susceptibility towards hydrolytic ring opening. As known from other lactams, the Nα ester moiety of the title compounds can be in an axial or equatorial conformation. Smaller ester groups were found to prefer equatorial positions, while larger ones occupy axial sites. N-substitution seems to promote axial conformations of the respective Nα group, with enantholactams being the only studied exception. In addition to the two common amide packing motifs, i.e. the R22(8) amide dimer (NH∙∙∙O/NH∙∙∙O) and the C(4) amide chain, a third graph-set was found: the R22(8) NH∙∙∙O/CH∙∙∙O=C heterodimers. In general, there seems to be a tendency for medium- sized lactams as well as lactams with small esters to form R22(8) amide dimers. Larger esters and enantholactam esters lead to C(4) amide chains. In this respect the formation of R22(8) N-H∙∙∙O/C-H∙∙∙O=C heterodimers should be seen as a remarkable exception

A Benchmark for Lidar Sensors in Fog: Is Detection Breaking Down?

Autonomous driving at level five does not only means self-driving in the sunshine. Adverse weather is especially critical because fog, rain, and snow degrade the perception of the environment. In this work, current state of the art light detection and ranging (lidar) sensors are tested in controlled conditions in a fog chamber. We present current problems and disturbance patterns for four different state of the art lidar systems. Moreover, we investigate how tuning internal parameters can improve their performance in bad weather situations. This is of great importance because most state of the art detection algorithms are based on undisturbed lidar data