⚛️ K₄[Fe(CN)₆] — Mössbauer tahlili

Fe²⁺ (LS, d⁶) • δ = −0.06 mm/s • ΔE_Q = 0.00 mm/s • Singlet • Diamagnit

K₄[Fe(CN)₆]

Mössbauer tahlili — to'liq profil

"Sariq qon tuzi" — Fe²⁺ LS klassikasi

K₄[Fe(CN)₆] — Fe²⁺ (LS, t₂g⁶) ning klassik namunasi. Kuchli maydon ligandlari (CN⁻) tufayli quyi spinli (LS) holat. Mössbauer spektri — singlet (δ = −0.06 mm/s, ΔE_Q = 0.00 mm/s). δ past — yuqori kovalentlik. ΔE_Q = 0 — sferik simmetriya.

Fe²⁺ (LS)

d⁶, t₂g⁶

S = 0

δ = −0.06

mm/s

izomer siljish

ΔE_Q = 0.00

mm/s

kvadrupol

Singlet

1 cho'qqi

spektr turi

📊 Mössbauer spektr simulyatori — K₄[Fe(CN)₆]

💎 K₄[Fe(CN)₆] ning o'ziga xosligi:

Fe²⁺ (LS, t₂g⁶) — nol kvadrupol bo'linishi (ΔE_Q = 0.00 mm/s). Sababi: t₂g⁶ konfiguratsiya to'liq to'lgan va sferik simmetrik. Elektr maydon gradienti (EFG) = 0 → spektr singlet (bitta cho'qqi).

δ (izomer siljish):-0.06 mm/s

Γ (chiziq kengligi):0.25 mm/s

Harorat (T):298 K

⚠️ ΔE_Q = 0.00

K₄[Fe(CN)₆] da kvadrupol bo'linishi yo'q — sferik simmetriya. Shuning uchun spektr singlet (bitta cho'qqi).

Mössbauer spektri (⁵⁷Fe, 14.4 keV):

-0.06 mm/s

ΔE_Q

0.00 mm/s

Spektr

Singlet

💡 Kuzatishlar:

Faqat 1 cho'qqi — ΔE_Q = 0 (sferik simmetriya)
Harorat pastlashi → intensivlik oshadi
δ siljishi → cho'qqi o'ngga yoki chapga siljiydi
Γ kichik → cho'qqi tor, yuqori rezolyutsiya

📐 δ va ΔE_Q tahlili — nima uchun singlet?

δ = −0.06 mm/s — nima anglatadi?

✓ Fe²⁺ — past oksidlanish (Fe³⁺ dan farqli)
✓ LS holat — t₂g⁶, s-elektron zichligi yuqori
✓ Kuchli π-akseptor (CN⁻) → δ past
✓ Kovalent bog' — Fe−C kuchli

Taqqoslash:

Fe²⁺ HS: δ ≈ 1.2 mm/s

Fe²⁺ LS: δ ≈ 0.0 mm/s ← K₄[Fe(CN)₆]

ΔE_Q = 0.00 mm/s — nima anglatadi?

✓ Nol EFG — sferik simmetriya
✓ t₂g⁶ to'liq to'lgan — asimmetriya yo'q
✓ ¹A₁g ground state — sferik
✓ Oktaedrik simmetriya — ideal

Taqqoslash:

Fe²⁺ HS: ΔE_Q ≈ 3.0 mm/s

Fe²⁺ LS: ΔE_Q = 0.0 mm/s ← K₄[Fe(CN)₆]

Elektron konfiguratsiya va EFG:

t₂g orbitallar:

↑↓↑↓↑↓

6 e⁻ (to'liq)

e_g orbitallar:

____

0 e⁻

t₂g⁶ → barcha elektronlar juft → sferik simmetriya → EFG = 0 → ΔE_Q = 0

💡 Nima uchun ΔE_Q = 0?

t₂g⁶ konfiguratsiyada barcha 6 ta elektron juftlashgan. Elektron zichligi sferik simmetrik — hech qanday asimmetriya yo'q. Elektr maydon gradienti (EFG) = 0 → kvadrupol bo'linishi = 0 → singlet.
Bu ¹A₁g ground state ning belgisi — oktaedrik kompleks uchun ideal holat.

🔄 K₄[Fe(CN)₆] vs K₃[Fe(CN)₆] — Mössbauer solishtirish

Xususiyat	K₄[Fe(CN)₆]	K₃[Fe(CN)₆]
Fe oksidlanish	+2	+3
Elektron konfiguratsiya	d⁶ (t₂g⁶)	d⁵ (t₂g⁵)
Spin holati	LS (S=0)	LS (S=1/2)
Toq elektronlar	0	1
Magnit holat	Diamagnit	Paramagnit
δ (mm/s)	−0.06	−0.12
ΔE_Q (mm/s)	0.00	0.38
H (Tesla)	0	0
Spektr turi	Singlet (1 cho'qqi)	Dublet (2 cho'qqi)
Ground state	¹A₁g (sferik)	²T₂g
Rang	Sariq	To'q qizil

💡 Asosiy farq:

K₄[Fe(CN)₆] — Fe²⁺ (t₂g⁶) → sferik simmetriya → EFG = 0 → singlet.
K₃[Fe(CN)₆] — Fe³⁺ (t₂g⁵) → bitta toq elektron → kichik EFG → dublet.
δ qiymatlari deyarli bir xil (−0.06 vs −0.12) — ikkalasi ham LS, kuchli kovalent bog'. Farq atigi 0.06 mm/s — Fe²⁺ da s-elektron zichligi biroz yuqori.

Spektr vizual solishtirish:

1 cho'qqi

2 cho'qqi

🔍 Nima uchun K₄[Fe(CN)₆] singlet, K₃[Fe(CN)₆] dublet?

💎 Asosiy qoida:

Mössbauer spektri shakli elektron konfiguratsiyasining simmetriyasiga bog'liq. Sferik simmetriya → singlet. Asimmetriya → dublet yoki sekstet.

K₄[Fe(CN)₆] — SINGLET

✓ Fe²⁺ (d⁶) → t₂g⁶
✓ Barcha elektronlar juftlashgan
✓ Elektron zichligi sferik
✓ EFG = 0
✓ ΔE_Q = 0
✓ Singlet (1 cho'qqi)

¹A₁g ground state

Sferik simmetrik

K₃[Fe(CN)₆] — DUBLET

✓ Fe³⁺ (d⁵) → t₂g⁵
✓ Bitta toq elektron
✓ Elektron zichligi asimmetrik
✓ EFG ≠ 0 (kichik)
✓ ΔE_Q = 0.38 mm/s
✓ Dublet (2 cho'qqi)

²T₂g ground state

Kichik asimmetriya

Umumiy qoida:

d⁰, d⁶ LS, d¹⁰:Singlet (sferik)

d¹, d⁵ LS, d⁷ LS:Dublet (kichik EFG)

d⁴ HS, d⁶ HS:Dublet (katta EFG)

Magnit tartiblangan:Sekstet (H ≠ 0)

🌡️ Haroratga bog'liqlik — Lamb-Mössbauer faktor

Lamb-Mössbauer faktor:

f = exp(−k²⟨x²⟩)

k — gamma-nur to'lqin vektori, ⟨x²⟩ — atom tebranishi

Harorat (T):298 K

80 K (suyuq N₂)298 K (xona)400 K

f (recoil-free)

0.742

Intensivlik

74.2%

💡 Amaliy maslahat:

K₄[Fe(CN)₆] uchun xona haroratida ham signal yetarli (f ≈ 0.74). Past haroratda (80 K) signal sezilarli kuchliroq bo'ladi (f ≈ 0.92). Diamagnit kompleks bo'lgani uchun magnit tartiblanish yo'q — harorat spektr shakliga ta'sir qilmaydi.

🏛️ Tarixiy kontekst — K₄[Fe(CN)₆] va Mössbauer

⚗️

1704 — Birinchi sintez

K₄[Fe(CN)₆] Prussian Blue dan olingan. "Sariq qon tuzi" deb nomlangan — K₃[Fe(CN)₆] dan farqli o'laroq.

⚛️

1960-70 — Mössbauer tadqiqotlari

K₄[Fe(CN)₆] — singlet spektrning klassik namunasi. Fe²⁺ LS ning sferik simmetriyasi aniq ko'rsatilgan.

🔬

1970-80 — Koordinatsion kimyo

K₄[Fe(CN)₆] — diamagnit kompleksning standarti. NMR, UV-Vis, Mössbauer — barcha usullar bilan o'rganilgan.

💡 K₄[Fe(CN)₆] ning ahamiyati:

Klassik LS Fe²⁺ namunasi — Mössbauer singlet
Elektrokimyoviy standart — [Fe(CN)₆]³⁻/⁴⁻ jufti
Diamagnit standart — NMR, magnit tadqiqotlar
Sferik simmetriya — ¹A₁g ground state

✅ Asosiy xulosalar

K₄[Fe(CN)₆] — Fe²⁺ LS (t₂g⁶, S=0)
δ = −0.06 mm/s — yuqori kovalentlik, kuchli π-akseptor
ΔE_Q = 0.00 mm/s — sferik simmetriya, EFG = 0
Spektr — singlet (1 cho'qqi)
H = 0 — diamagnit, magnit tartib yo'q
K₃[Fe(CN)₆] (Fe³⁺ LS) bilan solishtirganda — δ deyarli bir xil, ΔE_Q farqli
t₂g⁶ → barcha elektronlar juft → sferik simmetriya
¹A₁g ground state — oktaedrik kompleks uchun ideal holat
Mössbauer — Fe²⁺ LS ni aniq tasdiqlaydi

← K₃[Fe(CN)₆][Fe(H₂O)₆]²⁺ →