00923nas a2200181   4500008004100000245009400041210006900135260000800204300001600212520025700228100002200485700002200507700001700529700002300546700002100569700002400590856012700614       2008                        eng d00aMultiple weak supramolecular interactions stabilize a surprisingly twisted As2L3 assembly0 aMultiple weak supramolecular interactions stabilize a surprising  cOCT  a3936 - 39383 aA combined crystallographic, DFT and NMR spectroscopic study of a flexible As(2)(3) assembly reveals temperature dependent conformational behavior in solution and a highly asymmetric structure stabilized by As-pi and edge-to-face aromatic interactions.1 aPitt, Melanie, A.1 aZakharov, Lev, N.1 aVanka, Kumar1 aThompson, Ward, H.1 aLaird, Brian, B.1 aJohnson, Darren, W.  uhttps://library.ncl.res.in/content/multiple-weak-supramolecular-interactions-stabilize-surprisingly-twisted-as2l3-assembly02585nas a2200217   4500008004100000245016000041210006900201260000800270300001200278490000700290520176700297100002302064700002302087700002502110700001702135700002002152700002202172700002302194700002502217856012502242       2008                        eng d00aMultipoint anchoring of the [2.2.2.2]metacyclophane motif to a gold surface via self-assembly: coordination chemistry of a cyclic tetraisocyanide revisited0 aMultipoint anchoring of the 2222metacyclophane motif to a gold s  cMAY  a3284-910 v473 aA one-pot transformation of bis(2-isocyano-3-methylphenyl)ethane affords gram quantities of 8,16,24,32-tetraisocyano[2.2.2.2]metacyclophane ( 3). The solid state structure of 3 is remarkably close to the lowest energy conformation found on the potential energy landscape for 3 by DFT. In solution, the structure of metacyclophane 3 is mobile but can be locked in a rectangular gauche- anti- gauche- anti conformation by coordination of the isocyanide substituents to the [W(CO) 5] units to give [M] 4(mu 4-eta (1):eta (1):eta (1):eta (1)- 3) ( 5). The tetranuclear [M] 4(mu 4-eta (1):eta (1):eta (1):eta (1)- 3) motif featured in crystallographically characterized 5 may be present in several insoluble complexes of 3 previously described as mononuclear eta (4) species. A self-assembled monolayer of metacyclophane 3 is formed upon exposing a solution of 3 to the gold(111) surface with no precautions to exclude air or light. The monolayer nature of the film was confirmed by optical ellipsometry. The isocyanide stretching band for 3 shifts from 2119 cm (-1) in solution to 2175 cm (-1) upon chemisorption to metallic gold. The FTIR spectrum of the film indicates interaction of 3 with the gold surface via all four of its isocyanide anchors. No gold-facilitated oxidation of the -NC junctions was detected under ambient conditions. The energy cost associated with accessing the conformations of 3 suitable for mu 4-eta (1):eta (1):eta (1):eta (1) interaction of the molecule with the Au(111) surface is under 8 kcal/mol, a value that can be easily offset by formation of a gold-isocyanide bond. Two different mu 4-eta (1):eta (1):eta (1):eta (1) coordination arrangements of 3 with respect to gold atoms on the (111) face of the fcc Au lattice are suggested.1 aToriyama, Masaharu1 aMaher, Tiffany, R.1 aHolovics, Thomas, C.1 aVanka, Kumar1 aDay, Victor, W.1 aBerrie, Cindy, L.1 aThompson, Ward, H.1 aBarybin, Mikhail, V.  uhttps://library.ncl.res.in/content/multipoint-anchoring-2222metacyclophane-motif-gold-surface-self-assembly-coordination