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The charge-transfer reaction of decamethyiferrocene, Fe(C5Me5)2, Fc*, and 7,7,8,8-tetracyano-p-quinodimethane, TCNQ, has been characterized. Three major reaction products of varying stoichiometry, conductivity, and magnetism are formed: a 1-D metamagnetic 1:1 salt, [Fc*]'+[TCNQ]*~; a paramagnetic [Fc*]2,+ [TCNQ]22"; 1:1 dimeric salt, [Fc*]2'+ [TCNQ]22"; and a conducting 1:2 salt of [Fc*]'+[TCNQ]2~composition. The crystal and molecular structures of the 1:1 paramagnetic dimeric and metamagnetic one-dimensional salts were solved. The ions in the dimeric phase crystallize in the centrosymmetric monoclinic space group P2x/c with a = 9.708 (1) A, b = 12.211 (2) A, c = 23.585 (4) A, /? = 95.01 (1)°, Z = 4, and R = 0.058 for 3665 independent reflections. The structure consists of discrete stacks of DAAD dimeric (D = Fc*; A = TCNQ) units. One-dimensional stacking of ions is not observed. The decamethylferrocenium cations have average Fe-C distances of 2.096 (7) A, longer than the 2.050 A reported for neutral decamethyiferrocene. The C5Me5 rings appear eclipsed; however, as a result of the disorder only one ring was partially resolvable. The C5Me5 rings are essentially parallel to the TCNQ moieties and separated by 3.554 A. The TCNQ anions form a tight ag dimer (separated by a short distance of 3.147 A) and are slipped along the short TCNQ axis. Bonding arises through filling of the bonding ag dimer orbital. The magnetic susceptibility of powder samples of [Fc*]2,+[TCNQ2]22" obeys the Curie expression above 1.5 K suggesting very little magnetic coupling between the intradimer 5 = lJ2 Fe(III)'s which are separated by ~14 A. The [TCNQ]22" dimer is strongly antiferromagnetically coupled. The zero-field Mossbauer spectra of the dimeric phase above 1.4 K are typical of S' = '/2 [Fc*]'+ and exhibit rapidly relaxing paramagnetic behavior. However, relatively small external fields (<5 kG) are all that is necessary to induce slow paramagnetic relaxation and a substantial internal hyperfine field (~350 kG) at the decamethylferrocenium ions. Ions in the linear chain metamagnetic phase crystallize in the centrosymmetric triclinic space group PI. The unit cell at -106 °C is a = 8.635 (4) A, b = 9.384 (6) A, c = 10.635 (9) A; a = 116.76 (5)°, (3 = 112.58 (5)°; 7 = 72.49 (4)°, V = 701.8 A3, Z = 1, and Rv = 0.060 for 1156 reflections. The poorer quality of this structure is due to the inability to grow suitable crystals of this kinetically favored phase with respect to the thermodynamically favored dimeric phase. The structure consists of discrete one-dimensional chains comprised of alternating radical cation donors, D, and anion acceptors, A, i.e., -DADA-. The decamethylferrocenium cation has a staggered conformation with an average Fe-C distance of 2.090 A. This is equivalent to that observed for [Fc*]-+ in the dimeric phase. The C5Me5 rings are staggered and are canted with respect to the [TCNQ]'" moieties by 3.9°. The distance between the TCNQ and the C5Me5 rings is 3.43 A. The [TCNQ]"" anion represents the first structural character...

Anhydrous double nitrates of the lanthanides with potassium have been obtained in crystalline form. Crystallographic and spectroscopic studies are reported. K3Pr2(N03)9 is cubic, with a = 13.52 (1) A and space group 06-/>4332. The experimental density is 2.53 (3) g cm"3 and the computed value is 2.57 (1) g cm"3 for four formula weights. The structure was solved with 529 independent reflections recorded with an automatic diffractometer utilizing the -2 scan method. A least-squares refinement based on all reflections and with isotropic temperature factors for all atoms gave R = 0.058. Each Pr atom is surrounded by twelve oxygen atoms belonging to six nitrate groups which form a distorted icosahedron. The nitrates form two nonequivalent sets, each with its distinct bonding characteristics to the Pr and K atoms. Infrared and Raman studies confirm a strong interaction between the oxygen atoms and the lanthanide ion and indicate typical bidentate bonding. The optical spectrum of K3Nd2(N03)9 was investigated at ambient and at high pressure. The enhancement of hypersensitive transitions was noted and discussed in comparison to other crystals in which the Nd3+ exists in low site symmetries.

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