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The metal–pnictogen bond has rich and varied reactivity. The differences and similarities down the group and impacts on catalytic reactions with these elements is explored in this Feature.

Titanium compounds supported by the triamidoamine ligand (N3N, N(CH2CH2NSiMe33–)3) have been investigated for hydrophos-phination catalysis. The simple titanium alkyl compound (N3N)TiMe (2) demonstrate modest activity as a precatalyst for the pho-tocatalytic hydrophosphination of styrene, but the terminal phosphido compound, (N3N)TiPHPh (4), is inactive. Analysis of these reactions by EPR spectroscopy indicates that (N3N)TiMe undergoes homolytic Ti–C bond cleavage to achieve radical hydrophos-phination. This pathway was further supported in a radical trapping experiment. The phosphido derivative 4 does not produce rad-icals under similar conditions, despite undergoing facile migratory insertion reactions with polar substrates featuring C–N and C–O multiple bonds. Both nitrile and isonitrile substrates insert with ultimate formation of phosphaalkene products, a change in reactivi-ty as comparted to the zirconium congener. Molecular structures of (N3N)TiPHPh (4), (N3N)TiNBnC=PPh (5), and (N3N)TiN(H)C(Ph)=PPh (6) are reported.

Titanium compounds supported by the triamidoamine ligand (N3N, N(CH2CH2NSiMe33–)3) have been investigated for hydrophos-phination catalysis. The simple titanium alkyl compound (N3N)TiMe (2) demonstrate modest activity as a precatalyst for the pho-tocatalytic hydrophosphination of styrene, but the terminal phosphido compound, (N3N)TiPHPh (4), is inactive. Analysis of these reactions by EPR spectroscopy indicates that (N3N)TiMe undergoes homolytic Ti–C bond cleavage to achieve radical hydrophos-phination. This pathway was further supported in a radical trapping experiment. The phosphido derivative 4 does not produce rad-icals under similar conditions, despite undergoing facile migratory insertion reactions with polar substrates featuring C–N and C–O multiple bonds. Both nitrile and isonitrile substrates insert with ultimate formation of phosphaalkene products, a change in reactivi-ty as comparted to the zirconium congener. Molecular structures of (N3N)TiPHPh (4), (N3N)TiNBnC=PPh (5), and (N3N)TiN(H)C(Ph)=PPh (6) are reported.

Readily available and bench-stable Cu(acac)2 (1) addresses many challenges in exploratory hydrophosphination catalysis. Mechanistic investigations were performed to answer questions that remain about the reactivity of 1, the role of light in the catalysis, and to provide direction for further study. A divergent Hammett plot indicates differing mechanisms based on electron density at the alkene substrate. A radical process was eliminated based on trapping reactions and in-situ EPR experiments. Isotopic labeling experiments, a zwitterionic trapping experiment, stoichiometric model reactions, and catalytic reactions using proxy intermediates indicate that both conjugate addition and insertion-based mechanistic pathways occur with this system, depending on the unsaturated substrate. Computational analysis indicates that the lowest energy transition is a ligand-to-metal charge transfer (LMCT) from the phosphido ligand where the LUMO has significant Cu–P antibonding character, suggesting that a weakened Cu–P bond accelerates insertion under photocatalytic conditions. This hypothesis explains the greater activity of 1 compared to copper-catalyzed hydrophosphination reports and appears to be a general phenomenon for copper(I) catalysts. These results have been leveraged to achieve heretofore unknown catalytic hydrophosphination reactivity, namely the diastereoselective hydrophosphination of a tri-substituted styrene substrate.

This chapter considers the development of the relationship between Walter de la Mare and how it influenced the poetry of both poets. This is charted through their regular contributions to the Georgian Poetry anthologies edited by Edward Marsh between 1912 and 1922. The chapter also considers the origins, careers, and respective legacies of both poets.

This chapter describes the efforts of a collaborative team at the University of Vermont that has developed a first-year seminar led by near-peer leaders emphasizing the tools of success in science as the foundation for community building in the university’s largest science majors. The program has yielded greater persistence in these majors and greater retention at the university regardless of major, which indirectly supports positive coping with the pressures of the early science curriculum—retention markers that can only support future researchers.

The molecular structure of an iridium complex featuring a phenylphosphine ligand is described. Reaction of (POCOP)IrHCl (1, POCOP = 2,6-(tBu2PO)2C6H3–) with phenylphosphine gives (POC-OP)IrHCl(PH2Ph) (2) under mild conditions. Structural features are consistent with a classic pseudo-octahedral iridium compound with three neutral phosphine donors. Compound 1 is un-reactive at elevated temperature and unreactive toward excess phenylphosphine under condi-tions sampled.

Silicon-nitrogen bond formation is an important subfield in main group chemistry, and catalysis is an attractive route for efficient, selective formation of these bonds. Indeed, heterodehydrocoupling and N-silylation offer facile methods for the synthesis of small molecules through the coupling of primary, secondary, and tertiary silanes with N-containing substrates such as amines, carbazoles, indoles, and pyrroles. However, the reactivity of these catalytic systems is far from uniform, and critical issues are often encountered with product selectivity, conversions, substrate scope, catalyst activation, and in some instances, competing side reactions. Herein, a catalogue of catalysts and their reactivity for Si-N heterodehydrocoupling and N-silylation are reported.

A comparative study of amino phenoxide zirconium catalysts in the hydrophosphination of alkenes with diphenylphosphine reveals enhanced activity upon irradiation during catalysis, with conversions up to 10-fold greater than reactions in ambient light. The origin of improved reactivity is hypothesized to result from substrate insertion upon an n→d charge transfer of a Zr–P bond in the excited state of putative phosphido (Zr–PR2) intermediates. TD-DFT analysis reveals the lowest lying excited state in the proposed active catalysts are dominated by a P 3p→Zr 4d MLCT, presumably leading to enhanced catalysis. This hypothesis follows from triamidoamine-supported zirconium catalysts but demonstrates the generality of photocatalytic hydrophosphination with d0 metals.

Aromaticity and antiaromaticity, as defined by Huckel’s rule, are key ideas in organic chemistry, and are both exemplified in biphenylene1–3—a molecule that consists of two benzene rings joined by a four-membered ring at its core. Biphenylene analogues in which one of the benzene rings has been replaced by a different (4n + 2) π-electron system have so far been associated only with organic compounds4,5. In addition, efforts to prepare a zirconabiphenylene compound resulted in the isolation of a bis(alkyne) zirconocene complex instead6. Here we report the synthesis and characterization of, to our knowledge, the first 2-metallabiphenylene compounds. Single-crystal X-ray diffraction studies reveal that these complexes have nearly planar, 11-membered metallatricycles with metrical parameters that compare well with those reported for biphenylene. Nuclear magnetic resonance spectroscopy, in addition to nucleus-independent chemical shift calculations, provides evidence that these complexes contain an antiaromatic cyclobutadiene ring and an aromatic benzene ring. Furthermore, spectroscopic evidence, Kohn–Sham molecular orbital compositions and natural bond orbital calculations suggest covalency and delocalization of the uranium f2 electrons with the carbon-containing ligand. The synthesis of uranium- and thorium-containing metallabiphenylenes demonstrates the ability of the actinides to stabilize aromatic/antiaromatic structures where transition metals have failed.

Cu(acac)2 (1) is a highly active catalyst for the hydrophosphination of alkenes. Photocatalytic conditions are critical, and provide high conversions with unactivated substrates that have never before been reported with an air-stable catalyst or at ambient temperature. The commercial availability, ease of use, and broad substrate scope of compound 1 make hydrophosphination more available to synthetic chemists.

Eight ferrocene derivatives linked by either an ether, amine, or phenylacetylene moiety to a terminal ethynyl group were covalently deposited on glassy carbon electrodes by anodic electrochemical methods. The lithio activation method, in which the terminal hydrogen of the ethynyl group is replaced by a lithium atom before anodic oxidation, was successfully employed in all cases. Direct oxidation of the unactivated ethynyl group also resulted in surface deposition. Surface coverages between 1 x 10 ‐10 mol cm ‐2 and 14 x 10 ‐10 mol cm ‐2 were achieved. Cyclic voltammetry scans of the modified electrodes in pure electrolytes differed depending on the size of the supporting electrolyte anion, as little as half the current being measured for a [B(C 6 F 5 ) 4 ] ‐ vs. [PF 6 ] ‐ solution, suggesting differences in ion transport near the electrode surface. An ether‐linked ethynylferrocenium ion ( 5 + ) was isolated after electrolytic and chemical oxidation of 5 and characterized by X‐Ray crystallography as its [SbCl 6 ] ‐ salt.

Copper phosphido cluster Cu4(μ-PPh2)4(PtBu3)2 was synthesized by three synthetic methods and structurally characterized by X-ray diffraction and 1H, 31P, 13C and 31P HMBC NMR spectroscopy. Cu4(μ-PPh2)4(PtBu3)2 was also demonstrated to be a hydrophosphination pre-catalyst.

A comparative study of amino phenoxide zirconium catalysts in the hydrophosphination of alkenes with diphenylphosphine reveals enhanced activity upon irradiation. The origin of improved reactivity is hypothesized to result from substrate insertion upon an n to d charge transfer of a Zr–P bond in the excited state of putative phosphido (Zr–PR2) intermediates. TD-DFT analysis reveals the lowest lying excited state in the proposed active catalysts are dominated by a P 3p to Zr 4d MLCT, presumably leading to enhanced catalysis. This hypothesis follows from triamidoamine-supported zirconium catalysts but demonstrates the generality of photocatalytic hydrophosphination with d0 metals.

This chapter considers the contemporary reception of Wendy Cope’s debut collection, and its legacy. It also considers the themes of the collection, including her parodies of other contemporary poets and her invention of the character Jake/Jason Strugnell. The chapter also provides detailed close readings of poems in the collection.

This chapter considers the contemporary reception of Wendy Cope’s third collection, and its legacy. It also considers the themes of the collection, including her move away from parodies towards more personal poems. The chapter also provides detailed close readings of poems in the collection.

This chapter considers the contemporary reception of Wendy Cope’s fourth collection, and its legacy. It also considers the themes of the collection, including her poems about family relationships and childhood. The chapter also provides detailed close readings of poems in the collection.

This chapter considers the contemporary reception of Wendy Cope’s fifth collection, and its legacy. It also considers the themes of the collection, including her poems about marriage, ageing and Shakespeare. The chapter also provides detailed close readings of poems in the collection.

This chapter considers Cope’s poetry for children. It begins with a consideration of her pedagogical impulses and her work written to be read to young children in schools, and ends with consideration of her long poem The River Girl (Faber 1991). The chapter also considers some of her uncollected children’s poems. It provides close readings of key poems and sections of The River Girl.

This chapter considers the contemporary reception of Wendy Cope’s second collection, and its legacy. It also considers the themes of the collection, including her continued parodies of other contemporary poets and the final published poems using her character Jake/Jason Strugnell. It also provides close commentary on her developing themes of love and relationships. The chapter also provides detailed close readings of poems in the collection.

This chapter provides insight into Wendy Cope’s uncollected poems: those not included in her collections, and those that are as yet unpublished. It considers their points of connection or divergence with poems in her collections. The chapter ends with critical comment on work written or published since Anecdotal Evidence (2018), including her long poem St Hilda of Whitby, and where her poetry appears to be heading. As such, it serves a concluding function.

Wendy Cope (born 1945) is one of Britain's most popular poets: her first two collections have together sold almost half a million copies, and in 1998, when Ted Hughes died, she was the BBC listeners' choice to succeed him as Poet Laureate. She is also contrarian and sometimes controversial, and has been celebrated as one of the finest parodists of her, or any, generation. It is perhaps surprising, then, that her popular appeal has been met with critical near-silence. After five major collections, Cope has received only piecemeal critical attention, mostly confined to book reviews. This is the first in-depth study of her poetry. Drawing on Cope's published work, archival material and correspondence, as well as the available scholarship and journalism, Rory Waterman considers her main collections, her works for children and her uncollected and unpublished poems, with many close readings, and detailed considerations of her cultural and literary contexts and her poetic development.

The rationale to pursue long-term study of any system must be sound. Quick discoveries and emergent fields are more than temptations. They remind us to ask what are we gaining through continued study of any system. For triamidoamine-supported zirconium, there has been a great deal gained with yet more ahead. Initial study of the system taught much that is applied to catalysis. Cyclometalation of a trimethylsilyl substituent of the ancillary ligand, abbreviated (N

Reactions of [(dippe)PtMe(Et2O)][BArf4] (4[BArf4], dippe = 1,2-bis(diisopropylphosphino)ethane; Arf = 3,5-(CF3)2C6H3) with Mes2EH2 (Mes = mesityl) liberate methane and produce silylene, germylene, or stannylene products [(dippe)Pt(H)═EMes2][BArf4] (E = Si, 1[BArf4]; Ge, 8; Sn, 9). In contrast, treatment of 4[BArf4] with tertiary silanes HSiR3 (R = Ph, Et, OEt) failed to give the expected cationic silyl complexes but instead produced the bridging hydride [(dippe)Pt(μ-H)]2[BArf4]2 (10) along with the corresponding disilane Si2R6. Complex 10 reacts with primary stibines RSbH2 (R = Mes, dmp) to afford dimeric stibido complexes [(dippe)Pt(μ-SbHR)]2[BArf4]2 (R = Mes, 11; dmp, 12) via Sb–H bond activation.

Electrochemical oxidation of the cymantrene derivative MnCp(CO)2(IDiip), 1, (Cp = ƞ5-C5H5, IDiip = 1,3-bis(2,6-diisopropylphenyl)imidazole-2-ylidene) is a quasi-Nernstian one-electron process in dichloromethane/0.1 M [NBu4][PF6]. The E1/2 potential of the 10/+ couple, −0.34 V vs. ferrocene, is the most negative yet reported for a mono-substituted cymantrene derivative, reflecting the powerful electron-donating character of the N-heterocyclic carbene (NHC) IDiip ligand. The radical cation 1+ has been characterized by IR spectroscopy (νCO = 1958 and 2034 cm−1) and by X-ray crystallography as its [PF6]− salt. Compared to its neutral counterpart MnCp′(CO)2(IDiip) (Cp′ = ƞ5-C5H4Me), the Mn–CNHC bond distance in 1+ is lengthened by 0.031 A and the average M–C(O) bond distances are lengthened by 0.069 A. DFT-based computational results show that the largest contribution to the redox orbital of 10/+ is found at the metal atom (about 70% manganese-based in 1+). Comparison of the E1/2 potential of 1 with those of other mono-CO-substituted cymantene complexes allows an estimate of the “ligand electronic parameter” of the IDiip ligand as −0.27 V vs. NHE.