Coordination chemistry
A new Zn phenanthroline–maleate crystal
Open access · cc by · source: Europe PMC
Slow evaporation yields [Zn(phen)(maleate)(H2O)]·H2O, a distorted square-pyramidal complex with a 3.45 eV DFT gap and H-bond-dominated packing.
Study at a glance
- Design
- Other — Crystal structure, periodic DFT, and secondary MIC assays of a Zn–phenanthroline–maleate complex
- N
- Coordination-chemistry characterization — no cohort N
- Population
- Zn(II) phenanthroline/maleate coordination compound
- Outcome
- Structure, electronics, and weak antibacterial activity vs S. mutans
Structured fields used in claim comparison tables when every cited study has a complete layer.
Key findings
Zn is distorted square pyramidal in triclinic P-1 packing. Hirshfeld surfaces are dominated by H···O/O···H contacts (30.6%) with C···C π-stacking (9.0%). Periodic-DFT gives a 3.45 eV gap. Elemental analysis matched the hydrate formula. MIC against S. mutans was 1000 μg/mL, far weaker than gentamicin.
Methodology
They mixed phenanthroline, maleic acid, and ZnCl2, adjusted pH to about 7, and grew crystals over ~7 days. Single-crystal XRD, PXRD, FT-IR/Raman, DSC, Hirshfeld analysis, and CASTEP periodic-DFT mapped structure and electronics. Antibacterial MIC tests and docking were secondary.
Limitations
Antibacterial potency is modest and Gram-negative E. coli was inactive, so this is not a drug candidate. Docking ΔG values are computational, not measured binding. Optical/electronic properties were not tested in devices.
How this study connects
Role on claims
Each row is a claim on a concept or method page where this paper supports, challenges, or qualifies the statement. Roles are hand-checked — not a model guess.
Single-crystal XRD can lock a coordination geometry that powder methods only corroborate. A Zn phenanthroline–maleate hydrate is distorted square pyramidal in triclinic P-1; Hirshfeld surfaces are 30.6% H···O/O···H contacts and 9.0% C···C π-stacking. Periodic-DFT on that lattice gives a 3.45 eV gap — a computed number, not a measured spectrum — and the antibacterial MIC against S. mutans is 1000 μg/mL, far weaker than gentamicin.
Evidence for the claim as stated.
A powder pattern of a colloid and a single-crystal structure of a molecule are not the same XRD experiment. Fcc Ag peaks at 38.1–77.9° identify a metal phase and roughly a size regime; they do not give a coordination number, a space group of a molecular hydrate, or an E/Z ratio. Quoting 'XRD confirmed the structure' without saying powder versus single-crystal erases that.
Evidence for the claim as stated.
DFT is often a supporting assignment tool, not the primary result. Periodic-DFT on a Zn phenanthroline–maleate crystal gave a 3.45 eV gap; gas-phase heme-model pathways accompanied FT-ICR epoxidation rates with estimated ±30% rate error; ligand-centered versus metal-centered redox in cobalt PY4/PY3PZ complexes was parsed with DFT after electrocatalysis.
Evidence for the claim as stated.
Gas-phase ions, aqueous electrocatalysis, and a crystal gap are different DFT worlds. Naked [Feᴵⱽ(O)(porphyrin)]⁺ epoxidation in FT-ICR is not P450 Compound I in water; the Zn crystal gap was not tested in a device; cobalt HER overpotential is an electrochemical measurement with DFT as interpretation.
Evidence for the claim as stated.
On a Zn phenanthroline–maleate crystal and on microwave phage carbons, FT-IR/Raman sit in a characterisation stack. The Zn complex is distorted square pyramidal in P-1 with 30.6% H···O/O···H Hirshfeld contacts and a 3.45 eV periodic-DFT gap; MIC against S. mutans is 1000 μg/mL. Phage-derived particles emit at 380 nm (ΦF 14.8%) with Fe³⁺ LOD 8.0 μM — fluorescence, not IR, is the sensing observable.
Evidence for the claim as stated.
A Zn phenanthroline–maleate crystal is a hydrate whose formula matched elemental analysis; DSC and FT-IR/Raman sit beside SC-XRD. Geometry is distorted square pyramidal in P-1; Hirshfeld surfaces are 30.6% H···O/O···H and 9.0% C···C; periodic-DFT gap 3.45 eV; MIC 1000 μg/mL versus S. mutans. A hydrate is exactly the kind of solid TGA often quantifies — the teaching summary still does not quote a TGA water-loss percent.
Evidence for the claim as stated.
Composition from TGA-style thinking (how much is inorganic, how much is cargo) is not the function. MOF crystal size 260 nm–1 mm changes CO-photo-loading; hydrogel %DEE is a wet assay; Zn hydrate formula is elemental analysis. None of those papers' headline numbers are a TGA onset, and CO remains a toxic gas if mis-dosed.
Evidence for the claim as stated.
On a Zn phenanthroline–maleate hydrate, Raman sits with FT-IR, SC-XRD and periodic-DFT. The metal is distorted square pyramidal in triclinic P-1; Hirshfeld surfaces are 30.6% H···O/O···H and 9.0% C···C π-stacking; DFT gap 3.45 eV; MIC 1000 μg/mL versus S. mutans. Vibrational spectra fingerprint the ligands; they do not measure the gap or the MIC, and optical device tests were not done.
Evidence for the claim as stated.
Steady-state Raman of a solid and FSRS of a protein photocycle are not the same vibrational experiment. Zn-crystal Raman fingerprints ligands next to a 3.45 eV DFT gap; stibnite/carbon Raman characterises a composite whose headline is 455.8 versus 190.1 mA h g⁻¹; GFP FSRS/AIMD tracks 146 → 101 cm⁻¹ twists on a sub-picosecond shuttle. One sentence of 'Raman confirmed the material' cannot compare those papers.
Evidence for the claim as stated.
A method-index tag is not a guarantee that the teaching numbers came from Raman. The gold adt radical’s 21 μs TM is pulsed EPR in a glass; the Zn gap is DFT; the battery retention is galvanostatic cycling. Raman can be in the characterisation stack without being the quantity you should quote in an exam answer.
Evidence for the claim as stated.
Open questions
Tensions this paper is part of
From concept pages' “where studies disagree.” Disagreement means the same question; scope means different assays, populations, or outcomes.
A powder pattern of a colloid and a single-crystal structure of a molecule are not the same XRD experiment. Fcc Ag peaks at 38.1–77.9° identify a metal phase and roughly a size regime; they do not give a coordination number, a space group of a molecular hydrate, or an E/Z ratio. Quoting 'XRD confirmed the structure' without saying powder versus single-crystal erases that.
Gas-phase ions, aqueous electrocatalysis, and a crystal gap are different DFT worlds. Naked [Feᴵⱽ(O)(porphyrin)]⁺ epoxidation in FT-ICR is not P450 Compound I in water; the Zn crystal gap was not tested in a device; cobalt HER overpotential is an electrochemical measurement with DFT as interpretation.
Composition from TGA-style thinking (how much is inorganic, how much is cargo) is not the function. MOF crystal size 260 nm–1 mm changes CO-photo-loading; hydrogel %DEE is a wet assay; Zn hydrate formula is elemental analysis. None of those papers' headline numbers are a TGA onset, and CO remains a toxic gas if mis-dosed.
Steady-state Raman of a solid and FSRS of a protein photocycle are not the same vibrational experiment. Zn-crystal Raman fingerprints ligands next to a 3.45 eV DFT gap; stibnite/carbon Raman characterises a composite whose headline is 455.8 versus 190.1 mA h g⁻¹; GFP FSRS/AIMD tracks 146 → 101 cm⁻¹ twists on a sub-picosecond shuttle. One sentence of 'Raman confirmed the material' cannot compare those papers.
A method-index tag is not a guarantee that the teaching numbers came from Raman. The gold adt radical’s 21 μs TM is pulsed EPR in a glass; the Zn gap is DFT; the battery retention is galvanostatic cycling. Raman can be in the characterisation stack without being the quantity you should quote in an exam answer.
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