Absorption and luminescence spectra of dysprosium compound in non-aqueous solutions. Spectral intensity analysis.

Journal of Molecular Structure, 115 (1984) 421425 Elsevier Saence Publishers B-V., Amsterdam - E’nnted in The Netherlands

ABSORPTION

AND

SOLUTIONS.

SPECTRAL

LUMINESCENCE

J. LEGENDZIEWICZ', 'Institute

for

Sci aces,

Low

B.

DYSPROSIU:$

KELLER',

University

Temperature Wroclaw

50-950

OF

COtiPOUND

IN NCN-RCUEOUS

ANALYSIS.

G. OCZKO',

of Chemistry,

21nstitute

SPECTRA

INTENSITY

421

W. STREK2

of Wroclaw,

and

Structure

and

50-383

B. TRZEBIAT3WSti2 Wroclarr

Research,

Polish

(Poland) Academy

of

(Poland)

ABSTRACT Absorption and luminescence spectra of dysprosium compound were measured in non-aqueous solutions (alcohols, amides) within the region 5500 - 35000 cm-l. The oscillator stren ths of the f-f absorption bands were determined. The intensities of the Dy+ 2 ground state absorption were analyzed based on the Judd-0felt theory. A polanzability effect on the intensity of f-f transition was considered. The quenching mechanism of luminescence of the 4F,,, level for Dy+3 ion in non-aqueous solutions was discussed.

INTRODUCTION In our

latest

parameters and

have

tions

tried

usea

In the

sensitive

we

the

them

have

presented

Judd-Dfelt

with

the

satisfactory

relation

change

for

results

dysprosium

of identification

of

the s3x

compounds

of f-f

transi-

in the calculations. work

one

can

identification

those

spectra

for

on

the

intensity

of

the

matrix

find of

calculation

the

of dysprosium

transition

values

aquoion.

6H

15/2

We also

of

gap, a single

ing

luminescence

* 7

analysed

U (4) and vibration

of the

do the

transitions U(6)

not

level

,NH

for

and

R

2, (ref.1,

parameters,

intensities differ

influence and

the

in

the

the

I -IV of

greatly

variant)

the

hyper-

from

their

of polarizability

transitions

. It was considered

CH ,C:d,OH

4F9,2

of

assumed

where

’ x,2

l/2

have

results

transitions compounds

hypersensitive

elements

energy of

(ref.lj fron

to relate

present

maintaining from

Paper

calculation

too

with the

distance

dysprosium

in alcohol

previously

(ref.1).

both

great

influence

Me-L and

value of

on quenchamide

so-

lutions. EXPERIMENTAL The

preparation

tra were cm

-1

recorded

procedure

was

described

on a spectrophotometer

Cary

14 within

.

0022-2860/84/SO3.00

0 1984 Ekevler

Science

Publishers

B.V.

tne

Absorption

range

5500

spec-

- 35500

422

The

area

of

the absorption

integration

method

and

bands

were

expressed

calculated

in terms

numerically

of the

by

the

oscillator

strength

a particluar

value

graphical

'52 p = 4.32

x lo-'

I Eddo

,

'31 where

E is the

sition

energy

described

earlier

by excitation rent 100

decay runs

curve

The The

value CN,

of

to that

case

and

sampling

times

method

the

tran-

were

measured

recording

and

was

a cur-

comulation

up to

perchlorate

with

throughout,

us,

the

times

play

the

same

ire can

to the

ammount

measuerd

in quenching

concentration

assume

can of

according

of water,

be discussed

and in

luminescence.

one

The

of

of the be related

i(s)

~10-'~

= 0.3964

refractivity

error

observe

in the

the

parameters

are

oscillator

6H 9,2

for

gathered

strengths

alcohols

transition

so

are

inTablel. of

the

comparable

in solutions

which

good

identical

to the

might

point

of

formami-

for

refractivity

w is given

do not

by

of

show the

4f5d.

relation Pa,

Pab=[<(~)]2 in rough

to the

polarizability

R_ measured

R= Rw at a frequency

the

strength

mean

is formed

considerations

to exclusion

is proportional The

sphere

conformation

oscillator

molecules

PaLc[a(s)]2.

in our

calculation

low-lying

agreement

The

molar

coordination

ourselves

parameters

by the

(ref.2).

ligand

first

limit

of RX

in errors, the

cannot

limit

RA

2. The

therefore,

results

studies

might

and

in Table

solutions

'n'ecan,

case

strenth

DMSO.

in previous

polanzability

molar

for

given

difference

te-wavelength

The

the

6H -+6F 1512 11/2 ' they are for this

higher

of increasing

proximation

molecules

are

(ref.2).

considerable

Nevertheless,

the

decay

of

calculation

choppers,

is proportional

vibrations

of Gerchlorate

sphere

it was

OH

oscillator

molecules.

possibility

as

and

synchronous

applied

(ref.3)

transition much

diethylformamide In the

any

the

measured

aquoion,

by solvent

parameters

DISCUSSION

values

hypersensitive de,

by

been

is constant NH and

of Qx

spectra

two

dgsprosiun has

kHzoXti o 2

this

for

vethod

analyser.

measurements

of the

lifetimes

with

with

of photomultiplier

that

AND

The

Luminescence

N, laser

[Dy(C104)_, xH20]

to Horrock

RESULTS

an

coefficient

in cm-'.

(ref.1).

with

in our

of water

because

extinction

in a multi-channel

Since

terms

rmlar

o exoressed

square of

in the

apof

solvent infini-

423

N

° N

4-~

"

cJ

•

--

÷'

~'

-'I

~I

--I

4-I

-

-

ml

-

.

¢IJ

~

N

o

N

N

N

'~

I ~

~

O

k"%

×

~ o

c~

.4.-.~

e~

--

-

o

o .

.

L~

o i v

•

O0

•

t~ o,.1

c¢3 c¢3

~ i...,'~

~J

-I

-I

-

e~

I

O

4.-

% % %

~

~

r~

<

~

g

&

-'-

"a

424 TABLE The

2 luminescence

decay

times

of

Dy(C104)3

in non-aqueous

solutions

Decay

CKI

at room

temperature Solvent CH30H

3.75

C2H50H

4.80

DM50

11.00

FA

12.25

MFA

12.20

DMF

10.75

DEF

9.30

M - molecular

In a diagram

departure

This

point

may

the

proximately erable

low

error,

function

lengths seem

of solvent

differ

than

much

for

hypersensitive

that

&e-L

should

be

molecules

their

latter

conception,

the

in several and

but

the

in

solvate

just

a simple

values

OH

of

of 0~'~ to the ap-

causes

a consid-

polarizability

likewise.

into

because

account can

for

(amide, the

notice

Ln ions.

IR spectra

pure

length

can

of

of the

ior

polarizability

diethylformamide)

considerably

1) one rest

intensities

taken

solutions

the

overtone

is not

bond

Fig.

for

determination

transition

dependence

with

(see

transition

of the

that

intensity

precise

index.

is that

change

formamide,

obtained

intensities

Our

Eu+~

different results hypersen-

methylforrramide,

values

remain

too.

Oy *3 and

the

with

of the

almost

molar

constant

refrac-

(see

1).

The

.

.

lifetimes

perature. for

R,

dependence

not

of

- refractive

refractivity

contribution

possibility

nw

the

intensity

dimethylformamide

Fig.

to

where

transitions

tivity

the

is connected

to support

sitive

linear

or the

but

Another

molar

from

strengths

range

d - density,

Pt vers.

either

the oscillator within

weight,

of

a bigger

T

4.40

C3H70H

where

time

The

CH30H.

of

Dy(ClO,),

highest

The

snorter

lifeLimes

responsible for promoting ative

decay

may

be promoted

It 1s interesting

to note

NH vibrations

they

It means

the

a dominant

that

role

in different

'if_-_ ine was

do not

that effect

process.

for

alcohols

nonradiative

CH vibrations

in the

for

by CH

solutions

observed

(2950

is spite

are

linked

decay.

For

amide

cm-')

and

NH

of a fact

in a significant which

were

are

measured

FA solutions

closer

way

with

cm-')

FA and the

localized

in room the

the

solutions

(3450

that

and

OH vibrations the

nonradi-

vibrations.

iiFA possess

radiationless from

tem-

shortest

metal

the decay.

ion

play

425

DEF

18

20

22

24

26

2%

R

P’4 x104 25 23

DEF

IDyrc1os)oI

D,MF

i

0

MFA 0

1

0

DHSO

0

CH30H e i

4

6

8

Fig. 1. The dependence sensitive transitions

C2HSOH i0

12

14

e C3H70H 16

of the square root of on molar refractivity.

oscillator

strengths

of

hyper-

REFERENCES 1 2 3

J. Leqendziewicz, J. Legendziewiczi 92(1982) 205-207. W.'DeW.'Horrocks

G. Oczko

B. Keller Jr.

and

and B. Keller, and W. Strek,

D.R.

Sudnick,

J.

Polyhedron, Chem. Phys. Am.

Chem.

(1983) in press. Letters,

Sot.,

101

(1979)

334-340.