A stochastic search procedure for locating energy minimum structures was applied to the sec-butyl cation. A previously unreported structure 3' with strong H-hyperconjugative stabilization of the carbocation center was found at several levels of theory (HF, B3LYP, and MP2). The theoretical equilibrium isotope effect (EIE) for the monodeutero isotopomer of 3' (Keq = 1.4; t = -130 °C) indicates th...

In the title compound, C(30)H(39)OP, the P=O bond length is 1.4866 (12) Å and the P-C bond lengths range from 1.804 (2) to 1.808 (13) Å. The molecle is located on a crystallographic mirror plane. The methyl groups of one tert-butyl group are disordered over two sites in a 0.776 (4):0.224 (4) ratio.

The title compound, C(11)H(12)ClN(3)O(2), is essentially planar except for the n-but-oxy group [r.m.s. deviation from the least-squares plane = 0.0131 (1) Å for 11 non-H atoms]. An intra-molecular N-H⋯O inter-action results in the formation of an S(6) ring. The n-butoxy chain in the molecule is disordered over two sets of sites of equal occupancy.

Iminopropadienones, RN=C=C=C=O, can be generated from four different types of precursors in flash vacuum thermolysis reactions: 1,3-dioxane-4,6-diones 1, isoxazolopyrimidinones 2, pyridopyrimidinium olates 3, and pyridopyrimidinones 4. 2,6-Difluorophenyl-, 2,6-diethylphenyl-, o-tert-butylphenyl-, and mesityliminopropadienone have been directly observed by Ar matrix IR spectroscopy in one or mor...

The Ni(II) atom in the title compound, [Ni(C(24)H(43)P(2))(NO(3))], adopts a distorted square-planar geometry with the P atoms in a trans arrangement. The compound contains a twofold rotational axis with the nitrate group offset from this axis, except for an O atom of the nitrate group, generating two positions of 50% occupancy for the other atoms of the nitrate group.

In the crystal of the title compound, C(17)H(20)N(2)O(2), the molecules are linked by C-H⋯O interactions. Intra-molecular C-H⋯O and N-H⋯N hydrogen bonds also occur.

The title compound, C(24)H(40)O(2), lies on an inversion center with a half-mol-ecule in the asymmetric unit. The central dioxane ring adopts a chair conformation. The four-membered ring is slightly puckered with a butterfly angle of 13.50 (14)°.

In the title compound, C(10)H(20)O(4), the dioxane ring adopts a chair conformation. The tert-butyl group occupies an equatorial position, and is staggered with respect to the O atoms of the dioxane ring. In the crystal, mol-ecules are connected by O-H⋯O hydrogen-bonds into zigzag chains of R(4) (4)(8) and R(2) (2)(12) ring motifs that run parallel to the a axis.

In the title compound, (C(20)H(26)P)(2)[Pd(2)Cl(6)], the Pd(II) atom within the hexachloridodipalladate(II) dianion has a square-planar geometry. It resides on a centre of inversion with the asymmetric unit containing half of the dianion and one phospho-nium cation. Only weak C-H⋯π inter-actions are present in the crystal structure.

Crystals of the 2,4,6-tri-tert-butylphenoxyl radical have been isolated and characterized by X-ray diffraction, and calculations have been performed that give the distribution of spin density in the radical.