Volume 67, Issue 6

Transmetallation and oxidative substitution were utilized to prepare examples of group 14, group 6 and group 10 complexes from lithiated or chlorinated 4,4-dimethyl-2-(2-thienyl) oxazoline or its N-alkylated analogs. Two of the product types (2and 5) can be classified as a-thio or remote carbene complexes, depending on the position (3- or 5-) of attachment to the substituted thiophene ring. Spectroscopic measurements as well as crystal and molecular structure determinations clarified the bonding within the new compounds. Graphical Abstract Remote and α-Thio Carbene Complexes Derived from an Oxazolinylsubstituted Thiophene

Metalation of 3-phenyl-5-(2-pyridyl)pyrazole (HPz, 1) with alkyllithium and -zinc compounds in tetrahydrofuran (thf) yields dinuclear products [(thf)Li(Pz)] 2 (2) and [MeZn(Pz)] 2 (3), respectively. Magnesiation of 1 with diethylmagnesium in tetrahydrofuran in the presence of 1,4-dioxane leads to cocrystallization of mononuclear [(thf) 2 Mg(Pz) 2 ] (4a) and [(diox) 2 Mg(Pz) 2 ] (4b). Metalation of 1 with KH followed by a metathesis reaction with CaI 2 in tetrahydrofuran leads to the formation of dinuclear [{(thf) 2 Ca}(m-Pz) 3 Ca(Pz)] (5) with the calcium atoms in different coordination environments. The ligand precursor 1 crystallizes as a dimer with N-H···N bridges between the pyrazole fragments. The pyrazolate anions of the metal complexes 2 to 5 exhibit similar structural parameters regardless of a bridging or terminal coordination mode and the electronegativity of the coordinated metal. Graphical Abstract 3-Phenyl-5-(2-pyridyl)pyrazolato Complexes of Lithium, Magnesium, Calcium, and Zinc

The synthesis, spectroscopic characterization and crystal structures of new C-nitrosoaryl complexes of iridium(III) and rhodium(III) are reported. The reactions of the μ 2 -halogenido-bridged dimers [(η 5 -C 5 Me 5 )IrX 2 ] 2 [X = Cl (1a), Br (1b), I (1c)] and [(η 5 -C 5 Me 5 )RhCl 2 ] 2 (2a) with N,N-dimethyl- (3) and N,N-diethyl-4-nitrosoaniline (4) yield the mononuclear complexes [(η 5 - C 5 Me 5 )MX 2 (3)] [M = Ir, X = Cl (5a), Br (5b), I (5c);M= Rh, X = Cl (7a)] and [(η 5 -C 5 Me 5 )MX 2 (4)] [M = Ir, X = Cl (6a), Br (6b), I (6c); M = Rh, X = Cl (8a)]. All new compounds were characterized by their melting points, NMR, IR and mass spectra as well as in selected cases by UV/Vis spectroscopy. The X-ray structure analyses revealed a slightly distorted pseudo-octahedral configuration (“three-legged pianostool”) and σ-N coordination of the C-nitroso ligand. Graphical Abstract Reactivity of 4-Nitrosoanilines Towards Dimeric Halogenido-bridged Complexes of Iridium(III) and Rhodium(III) of the Type [(η 5 - C 5 Me 5 )MX 2 ] 2

The synthesis and the characterization of the complex salt [Au( t Bu 2 PH) 2 ][HCl 2 ] (2) resulting from the reaction of hydrogen tetrachloridoaurate(III) hydrate with t Bu 2 PH in dichloromethane at room temperature is reported. Single crystals of 2 have been analyzed by X-ray crystallography: monoclinic, P2 1 =c, Z = 12, a = 12:0805(3), b = 12:3729(4), c = 46:7506(13) Å ; ß = 90:948(2)°; V = 6986:9(3) Å3; T = 173(2) K. The hydrogen bihalide anions [HCl 2 ]- fill the interstices between the large complex cations [Au( t Bu 2 PH) 2 ] + in the crystal. Graphical Abstract Synthese und Kristallstruktur des Komplexsalzes [Au( t Bu 2 PH) 2 ][HCl 2 ] / Synthesis and Crystal Structure of the Complex Salt [Au( t Bu 2 PH) 2 ][HCl 2 ]

The bis(trimethyl)silylamido complex Na(THF){Fe[N(SiMe 3 ) 2 ] 3 } and the disilane tBu 3 SiSitBu 3 were obtained from the reaction of Fe[N(SiMe 3 ) 2 ] 3 with the sodium silanide Na(THF) 2 [SitBu 3 ] in a mixture of benzene and THF. Single crystals of Na(THF){Fe[N(SiMe 3 ) 2 ] 3 } suitable for X-ray diffraction were grown from the reaction solution at ambient temperature (orthorhombic, C222 1 , Z = 4). The solid-state structure features a contact-ion pair with two short N-Na contacts. The THF adducts {M(THF) 2 [N(SiMe 3 ) 2 ] 2 } reacted with 2,2´-bipyridine to give the corresponding complexes {M(2,2´bipy)[N(SiMe 3 ) 2 ] 2 } (M= Mn; Fe). Their structures (M= Fe: orthorhombic, Pca2 1 , Z = 8; M = Mn: orthorhombic, Pbca, Z = 8) feature monomeric units. The cyclic voltammogram of Fe[N(SiMe 3 ) 2 ] 3 revealed a reversible redox transition with the potential of -0;523 V (E ½ ), which was assigned to the Fe(III)[N(SiMe 3 ) 2 ] 3 → Fe(II)[N(SiMe3)2] - 3 redox transition, whereas the compounds {Fe(THF) 2 [N(SiMe 3 ) 2 ] 2 } (E ox = -0;379 V) and {Fe(2,2´bipy)[N(SiMe 3 ) 2 ] 2 } (E ox = -0;436 V) featured irreversible oxidation waves. The related manganese bis(trimethylsilyl)amido complexes {Mn(THF) 2 [N(SiMe 3 ) 2 ] 2 } (E ox = -0;458 V) and {Mn(2,2´bipy)[N(SiMe 3 ) 2 ] 2 } (E ox = -0513 V) also underwent irreversibile electron transfer processes. Graphical Abstract Eine elektrochemische und strukturelle Studie an den Eisensilylamiden Fe[N(SiMe 3 ) 2 ] 2 und Fe[N(SiMe 3 ) 2 ] 3 / An Electrochemical and Structural Study of the Iron Silylamides Fe[N(SiMe 3 ) 2 ] 2 and Fe[N(SiMe 3 ) 2 ] 3

Trichloroethene reacts with [Pt(PPh 3 ) 2 (C 2 H 4 )] at first π to the complex [Pt(PPh 3 ) 2 (η 2 -C 2 HCl 3 )] (1a), which isomerizes via the cis-isomer to the insoluble trans-[Pt(Cl)(η 1 -CH=CCl 2 )(PPh 3 ) 2 ] (2a). Both 1a and 2a react with PBu 3 to the corresponding tributylphosphane complexes 1b and 2b, respectively. From the reactions of [Ni(PR 3 ) 2 (C 2 H 4 )] (R = Me, Et, Bu) and C 2 HCl 3 only the products of oxidative addition trans-[Ni(Cl)(η 1 -CH=CCl 2 )(PR 3 ) 2 ] (3a - c) can be isolated. Hexachlorocyclopentadiene and hexabromocyclopentadiene react with [Pt(PPh 3 ) 2 (C 2 H 4 )] or [Ni(PR 3 ) 2 (C 2 H 4 )] (R = Ph, Me) to give highly colored solutions. Graphical Abstract Coordination Chemistry of Perhalogenated Cyclopentadienes and Alkynes, XXIX. The Reaction of Ni(0) and Pt(0) Phosphane Complexes with Trichloroethene, Hexachloro- and Hexabromocyclopentadiene

The synthesis of several phosphine Cu(I) complexes is reported, and their reactivity towards the solvents ethylenediamine (en) and dimethylformamide (dmf) has been investigated. CuX(PPh 3 ) [X = Cl (1), Br (2)], CuCl(PCy 3 ) (3) and CuCl(P i Pr 3 ) n [n = 1 (4), 2 (5)] were prepared according to adapted literature procedures. The complexes CuCl(P i Pr 3 )n were obtained in crystalline form from a hexane solution at -70 °C and structurally characterized for n = 1 and 2. Copper halide complexes of PCy 3 (3) and P i Pr 3 [n=1 (4)] gave colorless solutions in both en and dmf indicating the absence of Cu(II) ions. CuCl(P i Pr 3 ) 2 is stable in dmf solutions. By contrast, the complexes CuX(PPh 3 ) (X = Cl, Br) dissolve with blue color in en and with greenish-yellow color in dmf at higher temperatures under inert gas indicating a redox process affording Cu(II). At room temperature colorless crystals of CuX(PPh 3 )(en) 2 [X = Cl (6), Br (7)] and CuX(PPh 3 )(dmf) [X = Cl (8), Br (9)] were isolated from the solutions and analyzed by single-crystal X-ray diffraction. Graphical Abstract Reactivity of Cu(I) Compounds towards Ethylenediamine and Dimethylformamide: Crystal Structure of CuCl(P i Pr 3 ) n (n=1, 2), CuX(PPh 3 )(en) 2 (X=Cl, Br) and CuX(PPh 3 )(dmf)

1-Amino-3-nitroguanidine (ANQ, 2) was synthesized via hydrazinolysis of nitroguanidine (1). An appropriate Lewis structure of ANQ is drawn based on VB calculations. Due to its basicity, it can be protonated by strong mineral acids or acidic heterocycles. In order to synthesize new energetic materials the nitrate (3) and perchlorate (4) salts of 1-amino-3-nitroguanidine were synthesized by protonation of 2 with 40% nitric acid and 60% perchloric acid, respectively. 5-Nitrimino-1,4H-tetrazole obtained by reacting 5-amino-1H-tetrazole with 100% HNO 3 was used to synthesize the nitriminotetrazolate salt 5. Furthermore, the dinitramide salt 6 of 1-amino-3-nitroguanidine was synthesized by metathesis reaction of silver dinitramide and 1-amino-3-nitroguanidinium chloride. The dinitroguanidinate salt 7 was synthesized by protonation of 2 with 1,3-dinitroguanidine, which was prepared from nitroguanidine in anhydrous nitric acid/N 2 O 5 . All compounds were fully characterized by singlecrystal X-ray diffraction, vibrational spectroscopy (IR and Raman), multinuclear NMR spectroscopy, mass spectrometry, elemental analysis, and DSC measurements. The heats of formation of 2 - 7 were calculated using the atomization method based on CBS-4M enthalpies. With these values and the experimental (X-ray) densities several detonation parameters such as the detonation pressure, velocity, energy, and temperature were computed using the EXPLO5 code. In addition, the sensitivities towards impact, friction and electrical discharge were tested using the BAM drophammer, friction tester as well as a small-scale electrical discharge device. A Koenen test with 1-amino-3-nitroguanidinium nitrate (3) was carried out in order to evaluate its explosive performance and shipping classification. Graphical Abstract 1-Amino-3-nitroguanidine (ANQ) in High-performance Ionic Energetic Materials

The reaction of (C 6 F 5 ) 2 BCl with 8-lithio-N,N-dimethyl-1-naphthylamine (1) afforded the fivemembered ring system 8-bis(pentafluorophenyl)boryl-N,N-dimethyl-1-naphthylamine (2) with an intramolecular dative B-N bond. The compound was characterised by elemental analysis, NMR spectroscopy and single-crystal X-ray diffraction. Graphical Abstract An Intramolecular Boron Nitrogen Lewis Acid Base Pair on a Rigid Naphthyl Backbone

Several samples of solid solutions RE 16 Rh 11-x Z x (RE = La, Ce, Pr, Nd, Sm; Z = Ga, Zn, Cd,In, Sn, Sb, Pb, Bi) were synthesized by high-frequency melting of the elements in sealed tantalum ampoules. The samples were characterized by powder X-ray diffraction, and the structures of eight compounds were refined on the basis of single-crystal X-ray diffractometer data. The compounds crystallize with a centrosymmetric variant (space group P4⁄mbm) of the Ca 16 Sb 11 type (P4̄ 2 1 m). The relation between both structure types is discussed on the basis of a group-subgroup scheme. Only for La 16 Rh 8 Sn 3 we observed full rhodium-tin ordering. The striking structural motif is a chain of face-sharing square prisms (filled with tin) and anti-prisms (filled with rhodium). The La 16 Rh 8 Sn 3 structure is closely related to the structure types W 5 Si 3 , Ca 16 Sb 11 , Y 3 Rh 2 , Sm 26 Co 11 Ga 6 , Pu 31 Pt 20 , and Yb 36 Sn 23 and is the centrosymmetric n = 2 member of Parthé’s A 5n+6 B 3n+5 series. 119 Sn Mössbauer spectra resolved the two crystallographically independent tin sites of La 16 Rh 8 Sn 3 , while a Pr 16 Rh 9 Sb 2 sample shows only a singlet in its 121 Sb Mössbauer spectrum. Graphical Abstract Solid Solutions RE 16 Rh 11–x Z x (RE = La, Ce, Pr, Nd, Sm; Z = Ga, Zn, Cd, In, Sn, Sb, Pb, Bi) – Centrosymmetric n = 2 Variants of Parthé’s Homologous Series A 5n+6 B 3n+5

Dedicated to Professor Wolfgang Beck on the occasion of his 80 th birthday The lanthanum(III)-decaborate La 4 B 10 O 21 was synthesized under high-pressure/high-temperature conditions of 2.6 GPa and 750 ◦C in a Walker-type multianvil apparatus. The single-crystal structure determination revealed that La 4 B 10 O 21 is isotypic to Pr 4 B 10 O 21 . La 4 B 10 O 21 crystallizes monoclinically with four formula units in the space group P2 1 / n with the lattice parameters a = 716.7(2), b = 1971.5(4), c = 958.3(2) pm, and β = 93.7(1)◦. The three-dimensional boron-oxygen framework consists of [BO 4 ] 5− tetrahedra and trigonal-planar [BO 3 ] 3− groups. The structure contains four crystallographically different lanthanum ions. Two of the ions are surrounded by 10, one by 11, and the fourth one by 12 oxygen anions. In addition to IR-spectroscopic investigations, DFT calculations were performed to support the assignment of vibrational bands.

A modification of the previously developed synthetic approach towards dinuclear flexibly linked salphen complexes is successfully utilized for the preparation of heterodinuclear salphen dimers. A dinuclear salphen species with Pd(II) and Cr(III) centers bears a stronger structural resemblance to the related bis-Cr(III) compound than the corresponding mononuclear Cr(III) salphen complex. Therefore, it was considered as a more useful model for the comparison with the homobinuclear Cr(III) complex regarding the catalytic activity in the ring-opening polymerization of β-butyrolactone, for which a bimetallic catalytic mechanism seems to operate. The polymerization results again have shown a higher activity of the homobinuclear Cr(III) complex. Graphical Abstract Homo- and Hetero-bimetallic Flexibly Linked Dinuclear Salphen Complexes Homo- and Hetero-bimetallic Flexibly Linked Dinuclear Salphen Complexes

The pH-dependent dissociation and re-association behavior of casein proteins in alkaline environment was studied. In dilute aqueous solutions of pH = 12 and 13, casein was found to exist in the form of submicelles which represent the fundamental structural unit of casein micelles. Morphology and dimension of the casein submicelles were examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM), revealing spherical particles of ~ 10 - 30 nm in diameter. When the pH was increased to 14, unexpected re-association of casein submicelles occurred, resulting in the formation of large network aggregates at pH > 14. Furthermore, calcium phosphate was found to be the main driving force behind the re-association, as verified by comparative experiments employing Ca-depleted casein. Based on an analysis of potential interactions between the proteins, this re-association is ascribed to decreased electrostatic repulsion, strengthened hydrophobic attraction and formation of calcium phosphate linkages between casein proteins. Graphical Abstract Re-association Behavior of Casein Submicelles in Highly Alkaline Environments

Triaminoguanidinium chloride was transformed into 1,2,3-tris(benzylamino)guanidinium chloride (3-Cl) in two steps. Anion exchange allowed the preparation of further salts 3-X. The crystal and molecular structures of 3-Cl, 3-I, 3-CF 3 COO and 3-CF 3 SO 3 were determined. It was found that both the conformation of the cation and the nature of the anion determines the packing in the solid state. Interestingly, three different conformations of the cation were observed in the crystals. Graphical Abstract Derivatives of the Triaminoguanidinium Ion, 1. Synthesis, Crystal and Molecular Structures of 1,2,3-Tris(benzylamino)guanidinium Salts

An efficient synthetic route starting from 1,3,5-trimethylbenzene is described for binary 1,3,5- triazido-2,4,6-tricyanobenzene. Besides 1,3,5-triazido-2,4,6-tricyanobenzene, all intermediates have been isolated and fully characterized. Graphical Abstract An Efficient Route to 1,3,5-Triazido-2,4,6-tricyanobenzene