Unprotected dibenzo-7λ(3)-phosphanorbornadiene derivatives RPA (A = C(14)H(10) or anthracene; R = (t)Bu, dbabh = NA, HMDS = (Me(3)Si)(2)N, (i)Pr(2)N) are synthesized by treatment of the corresponding phosphorus dichloride RPCl(2) with MgA·3THF, in cold THF (~20% to 30% isolated yields). Anthracene and the corresponding cyclic phosphane (RP)(n) form as coproducts. Characteristic NMR features of the RPA derivatives include a doublet near 4 ppm in their (1)H NMR spectra and a triplet peak in the 175-212 ppm region of the (31)P NMR spectrum ((2)J(PH) ~14 Hz). The X-ray structures of the AN-PA and (HMDS)PA derivatives are discussed. Thermolysis of RPA benzene-d(6) solutions leads to anthracene extrusion. This process has a unimolecular kinetic profile for the (i)Pr(2)NPA derivative. The 7-phosphanorbornene anti-(i)Pr(2)NP(C(6)H(8)) could be synthesized (70% isolated yield) by thermolysis of (i)Pr(2)NPA in 1,3-cyclohexadiene.

In this study, we have developed a method to create Co6Se8 superatoms in which we program the metal-ligand bonds. We exclusively form the Co6Se8 core under simple reaction conditions with a facile separation of products that contain differential substitution of the core. The combination of Co2(CO)8 and PR3 with excess Se gives the differentially and directionally substituted superatoms, Co6Se8(CO)x(PR3)(6-x). The CO groups on the superatom can be exchanged quantitatively with phosphines and isonitriles. Substitution of the CO allows us to manipulate the type and length of chemical bridge between two redox-active superatomic centers in order to modulate intersuperatomic coupling. Linking two superatoms together allows us to form the simplest superatom molecule: a diatomic molecule. We extend the superatom molecule concept to link three superatoms together in a linear arrangement to form acyclic triatomic molecules. These superatom molecules have a rich electrochemical profile and chart a clear path to a whole family of superatom molecules with new and unusual collective properties.

Dibenzo-7-phosphanorbornadiene compounds, RPA (A = CH or anthracene), are investigated as phosphinidene sources upon thermally induced (70-90 °C) anthracene elimination. Analysis of substituent effects reveals that π-donating dialkylamide groups are paramount to successful phosphinidene transfer; poorer π-donors give reduced or no transfer. Substituent steric bulk is also implicated in successful transfer. Molecular beam mass spectrometry (MBMS) studies of each derivative reveal dialkylamide derivatives to be promising precursors for further gas-phase spectroscopic studies of phosphinidenes; in particular, we present evidence of direct detection of the dimethylamide derivative, [MeN═P]. Kinetic investigations of PrNPA thermolysis in 1,3-cyclohexadiene and/or benzene-d are consistent with a model of unimolecular fragmentation to yield free phosphinidene [PrN═P] as a transient reactive intermediate. This conclusion is probed by density functional theory (DFT) calculations, which favored a mechanistic model featuring free singlet aminophosphinidenes. The breadth of phosphinidene acceptors is expanded to unsaturated substrates beyond 1,3-dienes to include olefins and alkynes; this provides a new synthetic route to valuable amino-substituted phosphiranes and phosphirenes, respectively. Stereoselective phosphinidene transfer to olefins is consistent with singlet phosphinidene reactivity by analogy with the Skell hypothesis for singlet carbene addition to olefins.

Atomically defined interfaces that maximize the density of active sites and harness the electronic metal−support interaction are desirable to facilitate challenging multielectron transformations, but their synthesis remains a considerable challenge. We report the rational synthesis of the atomically defined metal chalcogenide nanopropeller Fe 3 Co 6 Se 8 L 6 (L = Ph 2 PNTol) featuring three Fe edge sites, and its ensuing catalytic activity for carbodiimide formation. The complex interaction between the Fe edges and Co 6 Se 8 support, including the interplay between oxidation state, substrate coordination, and metal−support interaction, is probed in detail using chemical and electrochemical methods, extensive single crystal X-ray diffraction, and electronic absorption and Mossbauer spectroscopy.

Aromaticity is predominantly associated with carbon-rich compounds but can also occur in all-inorganic ones. We report the synthesis of the diphosphatriazolate anion, a rare example of a planar aromatic inorganic species. Treatment of azide (N3(-)) in tetrahydrofuran solution with P2A2 (A = C14H10), a source of P2, produced P2N3(-), which we isolated as its [Na-kryptofix-221](+) salt in 22% yield and characterized by single-crystal x-ray diffraction. Salts [Na-kryptofix-221] [P2N3] and [Na-kryptofix-221] [P2(15)NN2] were analyzed by infrared and Raman spectroscopy, (15)N and (31)P nuclear magnetic resonance spectroscopy, and mass spectrometry. The formation of the P2N3(-) anion was investigated using density functional theory, and its aromatic character was confirmed by NICS (nucleus-independent chemical shift) and QTAIM (quantum theory of atoms in molecules) methods.