Zum Einfluß der PR3‐Liganden auf Bildung und Eigenschaften der Phosphinophosphiniden‐Komplexe [{η2‐tBu2P–P}Pt(PR3)2] und [{η2‐tBu2P1–P2}Pt(P3R3)(P4R′3)]

Coordination Chemistry of P‐rich Phosphanes and Silylphosphanes XXI The Influence of the PR₃ Ligands on Formation and Properties of the Phosphinophosphinidene Complexes [{η²‐^tBu₂P–P}Pt(PR₃)₂] and [{η²‐^tBu₂P¹–P²}Pt(P³R₃)(P⁴R′₃)] (R₃P)₂PtCl₂ and C₂H₄ yield the compounds [{η²‐C₂H₄}Pt(PR₃)₂] (PR₃ = PMe₃, PEt₃, PPhEt₂, PPh₂Et, PPh₂Me, PPh₂ⁱPr, PPh₂^tBu and P(p‐Tol)₃); which react with ^tBu₂P–P=PMe^tBu₂ to give the phosphinophosphinidene complexes [{η²‐^tBu₂P–P}Pt(PMe₃)₂], [{η²‐^tBu₂P–P}Pt(PEt₃)₂], [{η²‐^tBu₂P–P}Pt(PPhEt₂)₂], [{η²‐^tBu₂P–P}Pt(PPh₂Et)₂], [{η²‐^tBu₂P–P}Pt(PPh₂Me)₂], [{η²‐^tBu₂P–P}Pt(PPh₂ⁱPr], [{η²‐^tBu₂P–P}Pt(PPh₂^tBu)₂] and [{η²‐^tBu₂P–P}Pt(P(p‐Tol)₃)₂]. [{η²‐^tBu₂P–P}Pt(PPh₃)₂] reacts with PMe₃ and PEt₃ as well as with ^tBu₂PMe, PⁱPr₃ and P(c‐Hex)₃ by substituting one PPh₃ ligand to give [{η²‐^tBu₂P¹–P²}Pt(P³Me₃)(P⁴Ph₃)], [{η²‐^tBu₂P¹–P²}Pt(P³Ph₃)(P⁴Me₃)], [{η²‐^tBu₂P¹–P²}Pt(P³Et₃)(P⁴Ph₃)], [{η²‐^tBu₂P¹–P²}Pt(P³Me^tBu₂)(P⁴Ph₃)], [{η²‐^tBu₂P¹–P²}Pt(P³ⁱPr₃)(P⁴Ph₃)] and [{η²‐^tBu₂P¹–P²}Pt(P³(c‐Hex)₃)(P⁴Ph₃)]. With ^tBu₂PMe, [{η²‐^tBu₂P–P}Pt(P(p‐Tol)₃)₂] forms [{η²‐^tBu₂P¹–P²}Pt(P³Me^tBu₂)(P⁴(p‐Tol)₃)]. The NMR data of the compounds are given and discussed with respect to the influence of the PR₃ ligands.     

The Reaction of Ozone with the Hydroxide Ion: Mechanistic Considerations Based on Thermokinetic and Quantum Chemical Calculations and the Role of HO4− in Superoxide Dismutation

The reaction of OH^? with O₃ eventually leads to the formation of ^.OH radicals. In the original mechanistic concept (J. Staehelin, J. Hoigné, Environ. Sci. Technol. 1982 , 16, 676–681), it was suggested that the first step occurred by O transfer: OH^?+O₃→HO₂^?+O₂ and that ^.OH was generated in the subsequent reaction(s) of HO₂^? with O₃ (the peroxone process). This mechanistic concept has now been revised on the basis of thermokinetic and quantum chemical calculations. A one‐step O transfer such as that mentioned above would require the release of O₂ in its excited singlet state (¹O₂, O₂(¹Δ_g)); this state lies 95.5 kJ mol^?1 above the triplet ground state (³O₂, O₂(³Σ_g^?)). The low experimental rate constant of 70 M ^?1 s^?1 is not incompatible with such a reaction. However, according to our calculations, the reaction of OH^? with O₃ to form an adduct (OH^?+O₃→HO₄^?; ΔG=3.5 kJ mol^?1) is a much better candidate for the rate‐determining step as compared with the significantly more endergonic O transfer (ΔG=26.7 kJ mol^?1). Hence, we favor this reaction; all the more so as numerous precedents of similar ozone adduct formation are known in the literature. Three potential decay routes of the adduct HO₄^? have been probed: HO₄^?→HO₂^?+¹O₂ is spin allowed, but markedly endergonic (ΔG=23.2 kJ mol^?1). HO₄^?→HO₂^?+³O₂ is spin forbidden (ΔG=?73.3 kJ mol^?1). The decay into radicals, HO₄^?→HO₂^.+O₂^.?, is spin allowed and less endergonic (ΔG=14.8 kJ mol^?1) than HO₄^?→HO₂^?+¹O₂. It is thus HO₄^?→HO₂^.+O₂^.? by which HO₄^? decays. It is noted that a large contribution of the reverse of this reaction, HO₂^.+O₂^.?→HO₄^?, followed by HO₄^?→HO₂^?+³O₂, now explains why the measured rate of the bimolecular decay of HO₂^. and O₂^.? into HO₂^?+O₂ (k=1×10⁸ M ^?1 s^?1) is below diffusion controlled. Because k for the process HO₄^?→HO₂^.+O₂^.? is much larger than k for the reverse of OH^?+O₃→HO₄^?, the forward reaction OH^?+O₃→HO₄^? is practically irreversible.     

Molecular fragmentations: Part VIII. Structures and energies of mass spectral fragments derived from tetraphosphorus trisulphide

Molecular structures and energies have been calculated in the MNDO approximation, for P₄S₃ and its molecular ion P₄S₃⁺, and for the mass spectral fragment pairs: (P₃S₃⁺ + P), (P₃S₂⁺ + PS), (P₃S⁺ + PS₂), (P₂S₃⁺ + P₂), (P₂S₂⁺ + P₂S), (P₂S⁺ + P₂S₂), (P₂S₂), PS₃⁺ + P₃), (PS₂⁺ + P₃S), (PS⁺ + P₃S₂), and (PS⁺ + P₂S + PS). Three distinct energy minima were found for each of P₂S₂⁺ and P₂S₂, and two minima for each of P₂S⁺, P₂S, PS₃⁺, PS₃⁺, PS₂⁺, PS₂, P₃⁺ and P₃. The fragments arising from P₄ and P₄⁺ were also investigated. The structures are discussed in terms of the Jahn—Teller effect, whose predictions are fulfilled without exception.     

A Nitron-Polyvinylbenzyl Chloride Polymer to Selectively Remove Oxidizing Anions from Non-Oxidizing Anions. Removal of NO3 − and NO2 − from Polluted Waters

Abstract

A nitron-polyvinylbenzyl chloride polymer was found to have a strong preference for oxidizing anions such as NO₃ ^?, NO₂ ^?, ReO₄ ^?, MnO₄ ^?, C1O₄ ^?, C1O₃ ^?, and Cr₂O₇ ⁼ but not for the non-oxidizing anions SO₄ ⁼, HSO₄ ^?, H₂PO₄ ⁼, HPO₄ ⁼, PO₄ ⁼, OH^?, CO₃ ⁼, HCO₃ ^?, F^?, C1^?, and Br^?.     

Two organic–inorganic hybrid compounds constructed from [PMoV1MoVI7VIV2VV4O42]4− and different transition metal fragments

Two new organic–inorganic hybrid compounds, [Cu(phen)(prz)]₂[PMo^V₁Mo^VI₇V^IV₂V^V₄O₄₂]·4H₂O (1) and [Ag₂(phen)₄]₂[PMo^V₁Mo^VI₇V^IV₂V^V₄O₄₂] (2) (phen = 1,10-phenanthroline, prz = pyrazine), have been synthesized and characterized by IR, XPS, XRD, UV–vis, fluorescent spectra analyses, elemental analyses, X-ray diffraction analyses, TG analyses, and cyclic voltammetric measurements. Both compounds are formed by Keggin POM cores and transition metal fragments. Compound 1 exhibits an unprecedented 1-D chain structure constructed from [PMo^V₁Mo^VI₇V^IV₂V^V₄O₄₂]^4? and [Cu(phen)(prz)]²⁺ in the –A–B↑–C–B↓– linking mode. Compound 2 shows a supramolecular structure formed by [PMo^V₁Mo^VI₇V^IV₂V^V₄O₄₂]^4? and [Ag₂(phen)₄]²⁺.     

Recombination energy of N22+

The recombination energy of N₂²⁺ has been computed using N₂²⁺, N₂²⁺ and N₂ potential curves from the literature. Vibrational overlaps and energies liberated in the various N₂²⁺³∑^?_g,¹∑_g⁺, ³Π_u, ¹Π_u → N₂⁺(X²∑⁺_g, A ²∑⁺_g, A ²Π_u, B²∑_u⁺,C²∑_u⁺) vibronic transitions have been computed and used as input for determination of the N₂⁺ recombination energy.     

1,1,1,4,5,5,5-Heptafluoro-4-(trifluoromethyl)-2,3-pentanedione,a potent reagent for the synthesis of cyclic λ5σ5 phosphoranes

1,1,1,4,5,5,5-Heptafluoro-4-(trifluoromethyl)-2,3-pentanedione reacted with λ³σ³-phosphorus compounds, PR¹R²R³ (R¹ = CF₃, R² = R³ = Me, iPr, NEt₂; R¹ = NCO, R² = R³ = OMe, OEt, R²−R³ = OCH₂CH₂O, OCMe₂CMe₂O; R¹ = OSiMe₃, R² = R³ = OEt; R¹ = NEt₂, R² = R³ = OCH₂CF₃; R¹ = R² = Et₂N, R³ = OCH₂CF₃, OCH(CF₃)₂, OCH₂Ph, OC₆F₅) to give new 1,3,2λ⁵σ⁵-dioxaphospholenes. The first λ⁵σ⁵ phosphoranes with an OCN group bonded to phosphorus were obtained. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:109–113, 1998     

A flowing afterglow study of uranium tetraborohydride

Ionization-fragmentation of uranium(IV) tetraborohydride, U(BH₄)₄, by He⁺ and by N⁺/N₂⁺ yields, predominantly, U(BH₅)⁺ and U(B₂H₈)⁺, respectively. Attachment of thermal electrons yields U(BH₄)₄^? and ions of 1, 2, and 3 mass units less. Fluoride transfer with SF₆^?, BF₄^?, and UF_n^? (n = 5–7) and reactions with other small ions (O^?, O₂^?, NO₂^?, F^?, Cl^?, O₂⁺) are described.     

High-resolution UV photoelectron spectroscopy of diatomic halogens

Diatomic halogens are studied with UV photoelectron spectroscopy using new techniques to preserve high resolution even for reactive species. For the first time vibrational structure is observed on the ²Π_u,i (i = ^1/2,^3/2) states (F₂⁺, Cl₂⁺), the ²Σ_g⁺ states (F₂⁺, Cl₂⁺) and the Br₂⁺ (²Π_{u,$\text{3}\text{2}$}) state. On the ²Π_u,i states (F₂⁺, Cl₂⁺, Br₂⁺) spin-orbit splitting is resolved. Indications for a small potential barrier on the F₂⁺ (²Π_u,i) state for large internuclear distances are found. A new value for the spin-orbit splitting of the Cl₂⁺(²Π_g) state is presented (= ?725 cm^?1). The complementary nature of optical emission and photoelectron spectroscopy for small ions is demonstrated leading to a more complete picture of the F₂⁺ (²Π_u,i) and Cl₂⁺ (²Π_u,i) ionic states.     

Ternäre Thallium-Indium-Sulfide: Eine Zusammenfassung

Ternary Thallium Indium Sulfides: A Summary Combined thermal and X-Ray analyses in the ternary system Thallium—Indium—Sulfur show, that the two binary sections Tl₂S? In₂S₃ and TlS? InS contain ternary compounds with unique crystal structures. The chemical formulas of these ternary solids are TlIn₅S₈, TlIn₃S₅, TlInS₂ and Tl₃InS₃ for the section Tl₂S? In₂S₃ and TlIn₅S₆ as well as Tl₃In₅S₈ (metastable high temperature phase) for the section TlS? InS respectively. With TlIn₅S₇ an additional ternary solid could be detected, which is located outside the two sections. It is derived from the binary mixed valence compound In₆S₇ by complete substitution of In⁺ by Tl⁺. The following ionic formulations make the mixed valence character of the ternary Thallium—Indium-Sulfides reasonable: TlIn₅S₈ = Tl⁺(In³⁺)₅(S^2?)₈, TlIn₃S₅ = Tl⁺ (In³⁺)₃(S^2?)₅, TlInS₂ = Tl⁺In³⁺(S^2?)₂, Tl₃InS₃ = (Tl⁺)₃In³⁺ · (S^2?)₃, TlIn₅S₆ = Tl⁺([In₂]⁴⁺)₂In³⁺ (S^2?)₆, Tl₃In₅S₈ = 4 × [(Tl⁺)_0,75 · (In⁺)_0,25In³⁺(S^2?)₂], TlIn₅S₇ = Tl⁺[In₂]⁴⁺ (In³⁺)₃(S^2?)₇. All compounds contain Tl⁺-ions in a characteristic “lone pair coordination” of S^2? ions. Indium atoms however occur with the oxidation numbers +2 (formal, In₂ dumb bells with covalent In? In bonding) and +3 (with In³⁺ in tetrahedral and octahedral coordination of S^2?). Chemical preparation, crystal chemistry and general properties of the ternary solids are discussed, summarized and compared to each other.     

Interactions of Eu3+(aq) 7F, 5D1 and 5D0 levels with nitrate and inner-sphere (EuNO2+3)* exciplex formation

Steady-state and transient photokinetic and spectroscopic measurements on aqueous Eu(NO₃)₃ show different affinities of ⁷F, ⁵D₁ and ⁵D₀ Eu³⁺_aq towards nitrate ion. This may be rationalised by differences in the inner- and outer-shell hydration structures between ⁵D_O, ⁵D₁ Eu³⁺(_aq) and ⁷F Eu³⁺_(aq). Nitrate penetration into the inner-shell of Eu³⁺_(aq), and inner-coordination (EuNO²⁺₃)^* exciplex formation, occur solely in the long-lived ⁵D_O level of Eu³⁺_(aq).     

Solubilities and Ksp Values of the Less Soluble Anion Salts of “Nitron” (1,4-Diphenyl-3-anilino-1,2,4-triazoline)

Abstract

The solubilities and K_sp values at 25°C for the following anion salts of nitron are reported: VO₄ ⁼, Cro₄ ⁼, Cr₂O₇ ⁼,WO₄ ⁼, MoO₄ ⁼, BF₄ ^?, NO₃ ^?, NO₂ ^?, SeO₃ ⁼, S₂O₈ ⁼, SCN^?, Fe(CN)₆ ^?3, Fe(CN)₆ ^?4, Fe(CN)₅NO⁼, I^?, IO₄ ^?, CIO₃ ^?, CIO₄ ^?, BrO₃ ^?, and picrate^?. A total of 58 anions were tested.     

Transition-metal mediated heteroatom removal by reactions of FeL+ [L=O,C4H6, c-C5H6, c-C5H5, C6H6, C5H4(=CH2)] with furan,thiophene, and pyrrole in the gas phase

Reactions of Fe⁺ and FeL⁺ [L=O, C₄H₆, c-C₅H₆, C₅H₅, C₆H₆, C₅H₄(=CH₂)] with thiophene, furan, and pyrrole in the gas phase by using Fourier transform mass spectrometry are described. Fe⁺, Fe(C₅H₅)⁺, and FeC₆H ₆ ⁺ yield exclusive rapid adduct formation with thiophene, furan, and pyrrole. In addition, the iron-diene complexes [FeC₄H ₆ ⁺ and Fe(c-C₅H₆)⁺], as well as FeC₅H₄(=CH₂)⁺ and FeO⁺, are quite reactive. The most intriguing reaction is the predominant direct extrusion of CO from furan by FeC₄H₆ ⁺, Fe(c-C₅H₆)⁺, and FeC₅H₄(=CH₂)⁺. In addition, FeC₄H ₆ ⁺ and Fe(c-C₅H₆)⁺ cause minor amounts of HCN extrusion from pyrrole. Mechanisms are presented for these CO and HCN extrusion reactions. The absence of CS elimination from thiophene may be due to the higher energy requirements than those for CO extrusion from furan or HCN extrusion from pyrrole. The dominant reaction channel for reaction of Fe(c-C₅H₆)⁺ with pyrrole and thiophene is hydrogen-atom displacement, which implies D^O(Fa(N₅H₅)⁺-C₄H₄X)>D^O(Fe(C₅H₅)⁺-H)=46±5 kcal mol^?1. D^O(Fe⁺-C₄H₄S) and D^O(Fe⁺-C₄H₅N)=D^O(Fe⁺-C₄H₆)=48±5 kcal mol^?1. Finally, 55±5 kcal mol^?1=D^O(Fe⁺-C₆H₆)>D^O(Fe⁺-C₄H₄O)>D^O(Fe⁺-C₂H₄)=39.9±1.4 kcal mol^?1. FeO⁺ reacts rapidly with thiophene, furan, and pyrrole to yield initial loss of CO followed by additional neutral losses. D^O(Fe⁺-CS)>D^O(Fe⁺-C₄H₄S)≈48±5 kcal mol^?1 and D^O(Fe⁺-C₄H₅N)≈48±5 kcal mol^?1>D^O(Fe⁺-HCN)>D^O(Fe⁺-C₂H₄)=39.9±1.4 kcal mil^?1.     

Effect of Silica Gel ‘G’ on the Ion Exchange Behaviour of Antimonic Acid Thin Layers in The Chromatographic Study of Anions in Some Aqueous Organic Acid Systems: Determination of Ferricyanide and Dichromate Ions

Abstract

The ion exchange potential of antimonic acid and silica gel ‘G’ has been explored in thin layer chromatographic studies for the separation of anions. Several important and difficult binary separations of anions have been achieved as a result of these studies. Io^? ₃-Bro^? ₃, I^?-Io^? ₃, Io^? ₄-Io^? ₃, Io^? ₄-Po^?- ₄, Br^?-Bro^? ₃, Aso^?- ₄-Cro^?- ₄, S₂o^?- ₃-Po^?- ₄, CNS^?-S₂o^?- ₃, Io^? ₄-Cro^?- ₄, Bro^? ₃-Cro^?- ₄, Io^? ₃-Cr₂o^?- ₇ and s₂o₃-Cro^?- ₄ etc. are separations of analytical interest. Besides, a rapid microgram determination of [Fe(CN)₆]^3? (1–10 μg) and Cr₂o^2- ₇ (2–10 μg) ions have been made.     

CAS SCF Cl calculations for the 3Σ−g, 1Σ+g, 3Σ+u, and 5Δu states of Sc2

CAS SCF CI (SD) calculations have been carried out for the ³Σ^?_g, ¹Σ⁺_g, ³Σ⁺_u, and ⁵Δ_u states of Sc₂ using large gaussian basis sets. The ³Σ^?_g, ¹Σ⁺_g, and ³Σ⁺_u states arise from the ²D(4s² 3d¹) + ²D(4s² 3d¹) limit of Sc₂ and are found to be only weakly bound (D_c ≈ 0.06 eV and R_c ≈ 8.0a₀). The ⁵Δ_u state arises from the ²D(4s² 3d¹) + ⁴F(4s¹ 3d¹ 4p¹) atomic limit. This state is found to be strongly bound relative to its limits (D_c ≈ 0.8 eV and R_c ≈ 7.0a₀).     

The structure and energy of SiH+5. comparisons with CH+5 and BH5

Differences between SiH⁺₅ and CH⁺₅ are more significant than the similarities. The proton affinity of SiH₄ exceeds than of CH₄ by ≈25 kcal/mol. but the heat of hydrogenation of SiH⁺₃ is smaller than that of CH⁺₃ by nearly the same amount. Like CH⁺₅ the C₅ structures of SiH⁺₅ are preferred, but SiH⁺₅ is best regarded as a weaker SiH⁺₃—H₂ complex. D_3h, C_2v, and C_4v forms are much higher in energy and SiH⁺₅ should not undergo hydrogen scrambling (pseudorotation) readily, as does CH⁺₅ The neutral BH₅ is only weakly bound toward loss H₂, and the D_3h. C_2v, and C_4v forms are also high in energy. The contral-atom electronegativities, C⁺ > B > Si⁺, control this behavior. The electronegativities also determine the ability to bear positive charges. Thermodynamically. SiH⁺₅ and SiH⁺₃ are more stable than CH⁺₅ and CH⁺₃, respectively; hydride transfer occurs from SiH₄ to CH⁺₃ and proton transfer from CH⁺₅ to SiH₄.     

Darstellung der Iminiumsalze CF3?NXCF2+MF6− (X = CH3, F und M = As,Sb) und CF3?NCl = CF2+ AsF6−

Preparation of the Iminium Salts CF₃? NX?CF₂⁺MF₆^? (X = CH₃, F and M = As, Sb) and CF₃? NCl?CF₂⁺ AsF₆^? The preparation of the iminiumsalts CF₃? NX?CF₂⁺ MF₆^? (X = CH₃, F and M = As, Sb) and CF₃? NCl?CF₂⁺ AsF₆^? is reported. The salts were characterized by NMR and infrared spectroscopy. CF₃? NCH₃?CF₂⁺MF₆^? decompose into MF₅ and (CF₃)₂NCH₃.     

Collision-induced dissociations of deprotonated peptides,dipeptides and tripeptides with hydrogen and alkyl α groups. An aid to structure determination

The characteristic collision-induced dissociations of [M ? H]^? ions of dipeptides and tripeptides involve proton transfer to the carboxylate centre as a prelude to fragmentation. Dipeptides show the process NH₂CH(R¹)CONHCH(R²)CO₂^? → NH₂C(R¹)CONHCH(R²)CO₂H → ^?NHCH(R²)CO₂H + NH₂C(R¹)?C?O (R = H or alkyl) while tripeptides show the analogous processes NH₂CH(R¹)CONHCH(R²)CONHCH(R³)CO₂^? → NH₂CH(R¹)CONHC(R²)CONHCH(R³)CO₂^? → NHCH(R³)CO₂H + NH₂CH(R¹)CONHC(R²)?C?O and NH₂CH(R¹)CONHCH(R²)? CONHCH(R³)CO₂^? → NH₂C(R¹)CONHCH(R²)CONHCH(R³)CO₂H → ^?NHCH(R²)CONHCH(R³)CO₂H + NH₂C(R¹)?C?O. These fragmentations provide ready identification of the peptide.     

Kinetic Studies on the Oxidation of Germanium(II) with Chlorate by Polarographic Analysis

The rate of oxidation of Ge(II) chloride by large excess of ClO₂^? ions in HCl, NaCl and Na₂SO₄ mixed solutions was polarographically observed at various H₂O⁺ and Cl^? ion concentrations. The observed rate constant, k_obs, is expressed by k_o=K_obs/(ClO₃^?)={k₁,(H⁺)+k₂K₁(Cl^?)²+ K₃K₂(SO₄^2?)} (H⁺)/{(H⁺)¹+K₁(Cl^-)2 +K₂(SO₄^2?)} for the following reaction processes, The values were obtained aa k₁=1.5410^-3liter² mole^2? sec^-1, k₂=5.00×10^-2liter² mole^2? sec^-2 and k₂=4.30×10^-3liter² mole^2? sec^-2, K₁=1.80× 10^-2, K₂= 2.43×10^-2 mole liter^-1 at constant ionic strength I=0.50 M at 30°C.     

Luminescence Tuning of Upconversion Nanocrystals

Upconversion luminescence tuning of β‐NaYF₄ nanorods under 980 nm excitation has successfully been achieved by tridoping with Ln³⁺ ions with different electronic structures. The effects of Ce³⁺ ions on NaYF₄:Yb³⁺/Ho³⁺ as well as Gd³⁺ ions on NaYF₄:Yb³⁺/Tm³⁺(Er³⁺) have been studied in detail. By tridoping with Ce³⁺ ions, not only were unusual ⁵G₅→⁵I₇ and ⁵F₂/³K₈→⁵I₈ transitions from Ho³⁺ ions and 5d→4f transitions from Ce³⁺ ions observed in NaYF₄:Yb³⁺/Ho³⁺ nanorods, but also an increase in the intensity of ⁵F₅→⁵I₈ relative to ⁵S₂/⁵F₄→⁵I₈ with increasing Ce³⁺ concentration, which can be attributed to efficient energy transfers of ⁵I₆ (Ho)+²F_5/2 (Ce)→⁵I₇ (Ho)+²F_7/2 (Ce) and ⁵S₂/⁵F₄ (Ho)+²F_5/2 (Ce)→⁵F₅ (Ho)+²F_7/2 (Ce). Interestingly, with increasing pump power density, the luminescence of NaYF₄:Yb³⁺/Ho³⁺ nanorods is always dominated by the ⁵S₂/⁵F₄→⁵I₈ transition, whereas the luminescence of Ce³⁺‐tridoped NaYF₄:Yb³⁺/Ho³⁺ nanorods is dominated by the ⁵S₂/⁵F₄→⁵I₈ and ⁵G₅→⁵I₇ transitions in turn. These observations are discussed on the basis of a rate equation model. Furthermore, Gd³⁺‐tridoped NaYF₄:Yb³⁺/Tm³⁺(Er³⁺) nanorods can emit multicolor upconversion emissions spanning from the UV to the near‐infrared under 980 nm excitation. ⁶P_5/2→⁸S_7/2 (≈306 nm) and ⁶P_7/2→⁸S_7/2 (≈311 nm) transitions from Gd³⁺ ions were observed. In addition to the aforementioned luminescence properties, these Gd³⁺‐tridoped nanorods also exhibit paramagnetic behavior at room temperature and superparamagnetic behavior at 2 or 5 K.