Polysulfonylamines, CXL [1]. N-cycloalkyldimesylamines CnH2n-1N(SO2CH3)(2): Syntheses (n=3-6), solid-state molecular structures (n=4-6), and role of weak hydrogen bonds C-H center dot center dot center dot O in the crystal structures

The new disulfonylamines R-N(SO2Me)(2), where R = cyclopropyl (1), cyclobut yl (2), cyclopentyl (3) or cyclohexyl (4), were prepared according to an es tablished one-step procedure (condensation of RNH2 with two equivalents of MeSO2Cl, NaH as basic auxiliary). Whereas the structure determination for 1 was marred by severe disorder, compounds 2-4 have been characterized by lo w-temperature X-ray diffraction (2: monoclinic, space group P2(1), Z' = 2, pseudo-P2(1)/c packing; 3: triclinic, P (1) over bar, Z' = 1; 4: orthorhomb ic, Pbca, Z' = 1). The four independent molecules display puckered carbocyc les, whereby the electronegative (MeSO2)(2)N substituent occupies an equato rial position, leading to short intramolecular C-H . . .O contacts (2: angl es of ring pucker phi approximate to 30-33 degrees; 3: envelope conformatio n, phi approximate to 40; 4: chair conformation, phi (1) approximate to phi (2) = 51 degrees). In accordance with known congener structures, the C(sp( 3))-N(S)(2) moieties feature trigonal-planar N configurations and unusually long C-N bonds (ranges for 2-4: C-N 148.8-150.8 pm, S-N 166.6-168.9 pm, S- N-S 118.3-119.3). The three crystal packings are governed by a plethora of weak intermolecular hydrogen bonds C(sp(3))-H . . .O, and a thorough survey of these interactions reveals that the inductively activated methyl groups are distinctly more efficient hydrogen bond donors than the methine and me thylene ring groups. In each structure, the principal hydrogen bonds create layer substructures parallel to a unit cell face, which are cross-linked b y the remaining C-H . . .O contacts to form three-dimensional networks.