(18-Crown-6-[kappa]6O)(pyrazolato-[kappa]2N,N')-potassium(I)

The asymmetric unit of the title compound, [K(C3H3N2)(C12H24O6)], is composed of a potassium cation bonded to the six O atoms of a crown ether molecule and the two N atoms of a pyrazolate anion. The K...O distances range from 2.8416 (8) to 3.0025 (8) Å, and the two K...N distances are 2.7441 (11) and 2.7654 (11) Å. The K cation is displaced by 0.8437 (4) Å from the best plane through the six O atoms. The latter plane is almost perpendicular to the plane of the pyrazolate ring [dihedral angle 83.93 (3)°]. Key indicators: single-crystal X-ray study; T = 173 K; mean σ(C–C) = 0.002 A°; R factor = 0.026; wR factor = 0.066; data-to-parameter ratio = 16.5

Tetra­aceto­nitrile­lithium tetra­iso­thio­cyanato­borate

The crystal structure of the title salt, [Li(CH3CN)4][B(NCS)4], is composed of discrete cations and anions. Both the Li and B atoms show a tetra­hedral coordination by four equal ligands. The aceto­nitrile and iso­thio­cyanate ligands are linear. The bond angles at the B atom are close to the ideal tetra­hedral value [108.92 (18)–109.94 (16)°], but the bond angles at the Li atom show larger deviations [106.15 (17)–113.70 (17)°]

Di-μ-bromido-bis-[(diethyl ether-κO)(2,4,6-trimethylphenyl)magnesium] : the mesityl Grignard reagent

The crystal structure of the title compound, [Mg2Br2(C9H11)2(C4H10O)2], features a centrosymmetric two-centre magnesium complex with half a mol-ecule in the asymmetric unit. The Mg atom is in a considerably distorted Br2CO coordination. Bond lengths and angles are comparable with already published values. The crystal packing is stabilized by C-H⋯π inter-actions linking the complexes into sheets parallel to (0-11)

Dichloridobis(di-tert-butylmethylphosphine oxide-[kappa]O)diphenyltin(IV)

The complete molecule of the title compound, [Sn(C6H5)2Cl2(C9H21OP)2], is generated by crystallographic inversion symmetry, the Sn atom is located on a special position of site symmetry \overline{1}. The Sn atom adopts an all-trans SnC2O2Cl2 octahedral geometry. As a consequence of the bulky substituents at the O atom, the P-O-Sn bond angle is 163.9 (3)°. Key indicators: single-crystal X-ray study; T = 173 K; mean σ(C–C) = 0.012 Å; R factor = 0.058; wR factor = 0.099; data-to-parameter ratio = 18.6

Optimal gradual annuitization : quantifying the costs of switching to annuities

We compute the optimal dynamic asset allocation policy for a retiree with Epstein-Zin utility. The retiree can decide how much he consumes and how much he invests in stocks, bonds, and annuities. Pricing the annuities we account for asymmetric mortality beliefs and administration expenses. We show that the retiree does not purchase annuities only once but rather several times during retirement (gradual annuitization). We analyze the case in which the retiree is restricted to buy annuities only once and has to perform a (complete or partial) switching strategy. This restriction reduces both the utility and the demand for annuities

[my]-Bis(diphenylphosphanyl)borato-[kappa]2P:P'-bis[dicarbonyl([eta]5-cyclopentadienyl)iron(II)] tetrachloridoferrate(III) chloroform solvate

The title compound, [Fe2(C5H5)2(C24H22BP2)(CO)4][FeCl4]·CHCl3, is an oxidation product of CpFe(CO)2PPh2BH3. One pair of phenyl rings attached to the two different P atoms are almost parallel, as are the other pair [dihedral angles = 8.7 (5) and 8.9 (5)°]. The planes of the two cyclopentadienyl rings are inclined by 26.8 (7)° with respect to each other. The carbonyl groups at each Fe atom are almost perpendicular [C-Fe-C = 92.6 (6) and 94.3 (5)°]. Key indicators: single-crystal X-ray study; T = 173 K; mean σ(C–C) = 0.019 Å; R factor = 0.112; wR factor = 0.177; data-to-parameter ratio = 16.8

Tetra­butyl­ammonium tris­(methyl­sulfanylmeth­yl)phenyl­borate

In the title molecular salt, C16H36N+·C12H20BS3-, three of the four n-butyl chains show a trans conformation, whereas the fourth has the C—C—C—C torsion angle in a gauche conformation [-77.8 (5)°]. In the crystal, mol­ecules are packed in layers parallel to the (101) plane

My2-Acetone-diacetone[my3-tris­(trifluoro­meth­yl)methano­lato]bis­[my2-tris­(trifluoro­meth­yl)methano­lato]trilithium

The title compound, [Li3(C4F9O)3(C3H6O)3], features an open Li/O cube with an Li ion missing at one corner. Three of the four bridging O atoms of the cube carry a fluorinated tert-butyl residue, whereas the fourth is part of an acetone mol­ecule. Two of the Li atoms are further bonded to a non-bridging acetone mol­ecule. Two of the lithium ion coordination geometries are very distorted LiO4 tetra­hedra; the third could be described as a very distorted LiO3 T-shape with two distant F-atom neighbours. The Li[cdots, three dots, centered]Li contact distances for the three-coordinate Li+ ion [2.608 (14) and 2.631 (12) Å] are much shorter that the contact distance [2.940 (13) Å] between the tetra­hedrally coordinated species

Sodium pentafluorophenylborate

The crystal structure of the title compound, Na[(C6F5)BH3], is composed of discrete anions and cations. The sodium cations are surrounded by four anions with three short Na...B [2.848 (8), 2.842 (7) and 2.868 (8) Å] and two short Na...F contacts [2.348 (5) and 2.392 (5) Å], forming a three-dimensional network. The anion is the first structural example of a pentafluorophenyl ring carrying a BH3 group