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Towards Atom-by-Atom Fabrication: Mechanosynthetic Donation And Abstraction

Above: The molecular tool and general mechanosynthetic processes. (A) Overview of the probe and sample (above and below, respectively, not to scale) for IM-STM enabled mechanosynthesis. (B) Zoomed-in focus on the desired surface binding of the EAOGe–C2I molecular tool. (C) Chemical scheme for (B). (D) The deiodinated tool (EAOGe–C2
●). Approaching the tool to the probe surface and retracting may cause either mechanosynthetic (E) donation, yielding EAOGe● or (F) abstraction, yielding EAOGe–C2Si●.

Another part of the mechanosynthesis series from CBNNT, available at arxiv.org/abs/2606.13876 and focusing on efforts and molecular tool behavior on depassivated silicon surfaces. Still far too revolutionary to be called "more of the same."

And, for additional context, noting that long-time blogger and tracker of many things APM Brian Wang picked the paper up and processed notable items surrounding this and the previous paper in a short stack of posts on his nextbigfuture site:

Authors: Brandon Blue, Mathieu Morin, Alex Inayeh, Rosemary Cranston, Cameron J. Mackie, Marc Savoie, Adam Bottomley, Christian J. Imperiale, Zehra Ahmed, Rafik Addou, Aly Asani, Eduardo Barrera-Ramirez, Jeremy Barton, Doreen Cheng, Megan Cowie, Chris Deimert, Tyler Enright, James Zhangming Fan, Robert A. Freitas Jr., Alan T.K. Godfrey, Ryan Groome, Si Yue Guo, Kareem A. Clarcia, Aru Hill, Taleana Huff, Mark Jobes, Robert J. Kirby, Sam Lilak, Hadiya Ma, Adam C. Maahs, Oliver MacLean, Steven M. Maley, Michael Marshall, Terry McCallum, Ralph Merkle, Matthew Moses, Jonathan Myall, Ryan Plumadore, Adam Powell, Henry Rodriguez, Sam Rohe, Luis Sandoval, Khalil Sayed-Akhmad, Benjamin Scheffel, Kashif Tanveer, Bheeshmon Thanabalasingam, Denis A.B. Therien, Janice L. Wong, Reid Wotton, Cristina Yu, Damian G. Allis, Michael Drew, Matthew R. Kennedy, Tait Takatani, Marco Taucer, Dušan Vobornik, Ryan Yamachika, Mathieu Durand

CBN Nano Technologies, Inc. (CBNNT); Ottawa, K1Y 4W5, Canada

June 11, 2026

Enabled by inverted-mode scanning tunneling microscopy (IM-STM) and the use of functionalized molecular tools, we demonstrate positionally-controlled mechanosynthetic addition (donation) of carbon and subtraction (abstraction) of silicon atoms on a model build site: atomically clean and crystalline Si(100). The resulting structures represent the first demonstrations of an emerging ability to manipulate radical chemistry with positional control of specific atoms and moieties in 3D. Furthermore, by comparing the behavior of molecular tools designed for atomic donation versus abstraction, we highlight general principles governing molecular tool design for selective and reliable mechanosynthetic functionality.

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Free Astronomy Magazine – July-August 2026 Issue Available For Reading And Download

Above: NASA’s James Webb Space Telescope recently imaged the Sombrero Galaxy with its MIRI (Mid-Infrared Instrument), resolving the clumpy nature of the dust along the galaxy’s outer ring. The mid-infrared light highlights the gas and dust that are part of star formation taking place within the Sombrero Galaxy’s outer disk. The rings of the Sombrero Galaxy produce less than one solar mass of stars per year, in comparison to the Milky Way’s roughly two solar masses a year. It’s nHi,ot a particular hotbed of star formation.  The Sombrero Galaxy is around 30 million light-years from Earth in the constellation Virgo. Image: NASA, ESA, CSA, STScI

The most recent issue of Free Astronomy Magazine (July-August 2026) is available for your reading and downloading pleasure in English, Italian, Spanish, French, Arabic, and Chinese at www.astropublishing.com (and facebook).

For the interested but rushed (h/t Claude Sonnet 4.8):

3I/ATLAS formed in a far colder world than our own — ALMA made the first-ever deuterated-water (HDO, "semi-heavy water") measurement in an interstellar object. The comet holds ≥30× the HDO/H₂O of Solar System comets (40× Earth's oceans), fingerprinting a formation environment below ~30 K — chemically unlike our own system. H₂O itself fell below detection; the ratio was inferred via methanol-line excitation, in a narrow window six days after perihelion.

Persistent mismatch in the expansion of the local Universe — The H0 Distance Network (H0DN) collaboration folded decades of independent distance measurements into one framework and pinned the local Hubble constant at 73.50 ± 0.81 km/s/Mpc (~1% precision), versus ~67 from the CMB. Removing any single method barely moves it — effectively ruling out a single overlooked error and strengthening the case that the Hubble tension is real, possibly new physics.

Why does Jupiter have more large moons than Saturn? — NAOJ/Kyoto simulations: young Jupiter's strong magnetic field carved a "cavity" in its circumplanetary disk that kept large moons from spiraling in; Saturn lacked that field, so only Titan survived.

Webb redefines the boundary between planets and stars — JWST NIRCam coronagraphy of 29 Cygni b (~15 Jupiter masses). Metal enrichment (~150 Earths of heavy elements) plus orbit–spin alignment show it formed bottom-up by accretion, not stellar-style disk fragmentation — marking roughly the highest mass a planet can reach by accretion.

TNO 2002 XV93 has an atmosphere but shouldn't — A January 2024 stellar occultation observed from Japan showed gradual dimming consistent with a thin atmosphere on this ~500 km trans-Neptunian object. It should be too cold/low-gravity to hold one, and JWST sees no surface ices — so it must be recently replenished (interior outgassing or a comet impact).

WASP-189 b echoes the composition of its host star — IGRINS on Gemini South measured Mg and Si in this ultra-hot Jupiter's atmosphere simultaneously for the first time; its Mg/Si ratio matches the host star — the first direct observational confirmation of a foundational planet-formation assumption used to model rocky worlds.

VLBA maps turbulent "weather" in the Milky Way — Nearly a decade (2010–2019) of VLBA imaging of blazar TXS 2005+403 through the turbulent Cygnus region: the first clear radio detection of interstellar turbulence distorting a quasar, via refractive scattering on solar-system scales. Relevant to sharpening images like the EHT's.

The more massive star clusters emerge more quickly — Hubble + Webb (FEAST program) surveyed ~9,000 clusters in four galaxies (M51, M83, NGC 628, NGC 4449). The most massive clusters clear their natal gas in ~5 Myr vs. 7–8 Myr for lighter ones — meaning they start driving stellar feedback (and irradiating nearby protoplanetary disks) earlier.

This is how protoplanetary disks form — ALMA detected ENDTRANZ (Envelope–Disk Transition Zone) in protostar L1527 IRS: a ~16 AU zone where chaotic infalling gas gradually settles into ordered Keplerian rotation, seen as a predicted "jump" in specific angular momentum. Fills in the long-missing step of how disk material actually arrives.

DESI completes planned 3D map of the Universe — The five-year survey finished ahead of schedule: 47M+ galaxies/quasars + 20M stars (6× all prior measurements combined), the largest high-res 3D map ever. Early hints that dark energy may be evolving (not a constant) will now be tested on the full dataset; observations continue through 2028.

Rubin Observatory reveals over 11,000 new asteroids — From early-optimization data, the largest single asteroid batch submitted to the Minor Planet Center in a year: 11,000+ new asteroids, 33 near-Earth objects (none hazardous), and ~380 TNOs (two on extreme ~1,000 AU orbits). A preview of LSST, which should eventually triple the known asteroid census.

Sombrero Galaxy revealed like never before — DECam (Blanco 4 m, CTIO) deep image of M104, capturing its ~2,000 globular clusters, extended halo, and a stellar stream hinting at a past merger.

First light for PoET — ESO's Paranal solar ESPRESSO Telescope saw first light; a "solar telescope for planet hunters" that will characterize stellar-activity noise to unmask hidden exoplanets.

XRISM measures the hot wind in M82 — XRISM/Resolve clocked the superheated (~25 M°C) iron-bearing wind in the Cigar galaxy at ~3 million km/h via Doppler-broadened lines — fast enough to drive the galaxy-scale cool wind on its own, though a gas-budget puzzle remains.

ALMA witnesses star birth beyond the Milky Way — First core mass function measured outside our Galaxy (30 Dor-10, LMC): ~70 cores following a Salpeter-like trend despite the LMC's low metallicity, suggesting cloud fragmentation is largely environment-independent.

A Solar System in the making? — VLT/SPHERE + VLTI/GRAVITY+ confirmed a second forming planet (WISPIT 2 c) around young star WISPIT 2 — only the second system after PDS 70 with two directly imaged forming planets, and a likely young-Solar-System analog.

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Investigations Of Intramolecular And Intermolecular Noncovalent Interactions On Alkaline Earth Metal Complexes of –OC(Ph)(CF3)2

Above: The most-stable gas-phase configuration (1a, two views shown) exhibits π···H THF interactions (shown in gold) and F···H interactions (shown in green). The next most stable configurations (1c, shown as representative) exhibit a significant π···π interaction (shown in purple) and F···H interactions. In the higher energy configurations most similar to the crystal structure (crystal), there is no π···π interaction, only several F···H interactions.

What the crystal giveth, the gas phase taketh away.

Available open access (h/t Le Moyne College, past home of the great Prof. John McMahon) at pubs.acs.org/doi/10.1021/acs.inorgchem.6c01110. A few key sentences from the paper that nicely summarize what the theoretical work predicts compared to the crystallographic characterization.

However, in light of our theoretical findings for 1-4 that show the predicted M···F interactions in the gas phase are weaker than F···H and π···H, the reasons for the observed solid-state structures may in fact be more complex than M···F stabilization alone. Indeed, reliance on solid-state interatomic distances to determine the importance of relatively weak interactions such as M···F, F···H and π···H, assuming that shorter-is-stronger, may lead to overemphasis of their importance. Not all interactions are favorable, and other more favorable interactions elsewhere in the solid state may force two atoms to be nearer than expected.

A number of my previous papers explore how molecular geometries in even seemingly rigid organic frameworks (such as dodecahedrane) change due to crystal packing interactions, an effect clearly observable from symmetry breaking, shifts, and splittings in vibrational spectra. Among the alkali and alkali earth series, where crystallographic characterization has long been a basis for assessing the strengths and weaknesses of observed interactions based on interatomic separations, this new study of Mg…F, Ca…F, and Sr…F interactions in both the solid-state (crystallography) and in the gas/solution-phase (theory) reveal that the complexes in the absence of crystal packing interactions take on different geometries and, as a consequence, interactions one might characterize as "stabilizing" due to their existing below reported cut-off values from other crystal studies go away in favor of other, more favorable intramolecular interactions being available. Obviously, this speaks to the balance between intramolecular and intermolecular stabilization in the solid-state, something being considered specifically for the Mg…F series in ongoing work.

Authors: Anna Y. O’Brien, Yuriko Takahashi, Miriam Gillett-Kunnath, Damian G. Allis, Ana Torvisco, and Karin Ruhlandt-Senge

ABSTRACT: Alkaline earth metals are relatively abundant, inexpensive and desirable as metal−organic complexes for applications in electronics and catalysis. Synthetic challenges arise from their high reactivity and the tendency of their compounds to form aggregates. Previous work demonstrated that certain fluorinated alkoxide ligands improved the volatility of alkaline earth metal and mixed-metal complexes, in part due to the presence of noncovalent secondary M···F interactions. This work further explores the impact of secondary interactions on their structure. The fluorinated alkoxide 2,2,2,2′,2′,2′-hexafluorocumyl alkoxide, −OC(Ph)(CF3)2 (“L”), introduces the possibility of both M···F and M···π stabilizing interactions. Synthetic methods including alkane elimination (Mg), direct metalation(Ca,Sr,Ba), and protonolysis (Ba) with complexation to L in the controlled presence and/or absence of neutral donors afforded MgL2(thf)2, (1) trans-CaL2(thf)4 (2), cis-SrL2(thf)4 (3), Sr2(μ2-L)3L(thf)3 (4), Sr3(μ2-L)4L2(OEt2)2 (5), [Ba(μ2-L)2]n·1/4 (OEt2) (6), and [Ba(μ2-L)2]n (7). Structural characterization shows the number of secondary interactions increase for the heavier metals and decreasing presence of the neutral donor, coinciding with increased nuclearity. Computational studies predict notable differences between preferred configurations that might exist in the gas-phase and those observed in the solid state.